The World Trade Center and Pentagon Tragedy
(This page is updated as new information is found and time permits.)

Last updated 07/19/04 8:07 am

FEMA/ASCE Building Performance Study Released
The Pentagon Building Performance Report is now available
NEW Engineering News Record Cover Story: Skyscrapers' Supporters Infuriated by Fire Fearmongers

[Observances marking 9/11 Anniversary] [NIST Investigation][FEMA/ASCE Report] [Six Plans for Ground Zero] [Building Code Revisions] [Analysis of Collapse] [Building condition around WTC site] [WTC Below grade conditions] [WTC site clean-up][Occupancy of the WTC] [Structural Investigation Teams] [Pentagon site] [In Memoriam - Penn State] [First Hand Reports - NYC] [First Hand Reports - Pentagon] [Reports from others] [Pictures etc.][Pictures that help in analysis of collapse] [WTC facts: Design and Construction] [Insurance Industry response][PSU AE Faculty comments] [Patriotic Images] [Rumors debunked] [In Memoriam] [Tributes] [Personal writings][Filling the Void: What happens to the site][Rebuilding Wall Street] [Miscellaneous] [General Political Information]

American Red Cross	NY Fireman's Fund	Salvation Army	United Way

Observances marking 9/11 Anniversary

• 08/19/02 World leaders will light an eternal flame, the governor will deliver the Gettysburg Address, and

former Mayor Rudolph Giuliani will lead a reading of the names of 2,823 victims during a day of ``simple
and powerful'' observances marking the anniversary of the World Trade Center attack.

NIST Investigation

• 07/08/02 The National Institute of Standards and Technology has begun its effort, funded by Congress, to investigate the collapse of the World Trade Center. Their web page will likely keep the public updated.
• 07/08/02 The proposed NIST plan is available on line.
• 07/08/02 They conducted an open meeting on their plan in NYC on June 24. The audio and electronic print transcripts are available.
• 07/08/02 This Washington Post article reports on some of that meeting.
• 07/24/02 A new bill will give NIST investigatory power, similar to the NTSB, in building collapses.
• 07/30/02 ENR reports on the bill to set up teams for building probes.
• 07/30/02 ENR Editorial "No Need for a Solution In Search of Problem" (listed second on this page)
• 08/21/02 Federal officials were to launch a two-year, $16 million investigation of the World Trade Center collapse on Sept.11. The Senate has not approved subpoena power for NIST.
• 08/21/02 NIST will officially launch their investigation with a news conference on August 21.This webcast will be archived soon.
• 08/22/02 NIST News release covering initiation of investigation.
• 08/22/02 The Final NIST plan for their 24 month study.
• 08/22/02 Fact sheet summary.
• 07/05/04 ENR reports on latest NIST update. Columns Likely Failed First in Terrorist-Triggered WTC Fires (6/28/2004)

FEMA/ASCE Building Response Team Report

• 04/08/02 The New York Times comments on the FEMA/ASCE Team report that they obtained. Their conclusions are not necessarily an accurate interpretation of what the report actually says.
• 04/08/02 The New York Times in an article "U.S. Report on Trade Center Echoes Lessons of Past Disasters," again draws conclusions that are not necessarily consistent with the facts of building response to fire. The April 8, 2002 issue of ENR contains a well written editorial "Office Towers Are Safest Buildings of Them All" critique of the NYT article and should be read by all who are interested in the assessment of building response to fire.
• 07/24/02 Letter to the editor discussing above editorial.
• 04/17/02 ENR reports on the Building Response Team (FEMA/ASCE) presentations at the ASCE Structures Congress pointing out that the final report will recommend no code changes.
• 04/30/02 NOVA will air a program April 30, based on the FEMA/ASCE investigation.
• 04/30/02 The designers of the World Trade Center did not sacrifice safety to save money and should not be blamed for the loss of more than 2,800 lives in the collapse of the 110-story twin towers. "It's my opinion that they did not skimp at all," said the engineer, W. Gene Corley who heads the FEMA/ASCE team.
• 05/15/02 NYT Discussion of the FEMA/ASCE report prior to its release (May 1)
• 05/03/02 The final report of the FEMA/ASCE Building Performance Study Team has been released. It is found on the web page of the House Committee on Science, in *.pdf format.
• 05/15/02 William Faschan, of Leslie E. Roberston Associates discusses the process of designing skyscrapers by requiring anticipation of the unknown.
• 05/15/02 Reuters reports on the FEMA/ASCE and how it is virtually impossible to make buildings strong enough to withstand the massive damage that brought down the World Trade Center towers.
• 05/15/02 The Washington Post reports on the FEMA/ASCE report.
• 05/15/02 A review of the NOVA TV presentation.
• 05/15/02 ASCE News release on the FEMA/ASCE report.
• 05/15/02 The Financial Times reports on the release of the FEMA/ASCE report.
• 05/15/02 It is encouraging at just how well pointed Nadine Post and her colleagues at ENR are in getting to the heart of the issues from FEMA/ASCE WTC report. This is an outstanding article by folks who know engineering.
• 05/16/02 The Structural Engineers of California listserv has discussed issues generated by the NOVA program. Three specific questions and comments may be of interest. Message 794, message 874, and message 924.
• 06/09/04 A series of articles in Plumbing Engineer assesses the FEMA report, the NIST investigation and the push to modify building codes. A must read for anyone interested in a reasoned review of where we are headed. The combined series is available here.
• 06/09/04 ENR has once again stepped up and presented a hard hitting report on the fear mongers centering heri efforts on teh WTC in a cover story: FIRE PROTECTION: Skyscrapers' Supporters Infuriated By Fire Fearmongers. Antagonists, feeding on post-9/11 jitters, magnify danger of towering infernos (6/7/2004 Issue) By Nadine M. Post. This link will take you to the first of a 5 page article.The articles by Richard Schulte that are referred to here are linked directly above.

• 07/23/02 The Lower Manhattan Development Corporation web page.
• 07/23/02 The LMDC Site link with the plans and all the associated graphics
• 07/23/02 Schedule for developing the official plan.
• 07/23/02 The six plans for Ground Zero put forth by the Lower Manhattan Development Corporation have many similarities.
• 07/23/02 Myths about the redevelopment plans.
• 07/24/02 All the competing plans call for a memorial park - continued discussion.
• 07/24/02 CNN discusses the 6 options.
• 07/24/02 The six plans 1, 2,3, 4, 5, 6. Slide show of these images.
• 07/24/02 Commercial space mix in redevelopment could impact revenues and race for governor.
• 07/24/02 Six plans seen as a starting point.
• 07/24/02 Six plans interactive feature form NYT
• 07/24/02 Upcoming Town Meeting expected to attract 5000 people.
• 07/24/02 Town meeting discusses the six plans and the future of Ground Zero.
• 07/24/02 NYT Editorial calls proposals dreary.
• 07/24/02 The public's call for a slower planning process and less commercial space on the World Trade Center site leaves officials with some tough decisions.
• 07/24/02 Officials say it may take longer than planned to choose a final design because of complaints about the six

existing proposals for the site.
• 07/24/02 LATimes asks "Where's the imagination?"
• 07/24/02 Chicago Tribune says the plans are "at best underwhelming."
• 07/24/02 Chicago Tribune slide show including views from the Hudson River.
• 07/24/02 Washington Post "Same Old Stuff."
• 07/24/02 Washington Post video of proposals.
• 07/24/02 NYT Some designs are not so bad.
• 07/24/02 NYT OpEd calls for going back to the drawing board.
• 07/30/02 The shopping complex that ate the WTC Memorial. A critique in "Slate".
• 07/30/02 The Wall Street Journal Opinion Journal suggests NYC Building Code has to go.
• 07/30/02 Gov. Pataki suggests that the plans must look beyond ground zero.
• 07/30/02 Gov. Pataki urges more flexibility in rebuilding at Ground Zero.
• 07/30/02 Another appraisal of the plans from NYT.
• 07/30/02 In trying to please all, WTC plans fail to please - from USNews.com
• 07/30/02 A tangle of interests are at work in Lower Manhattan seeking to influence the rebuilding.
• 07/30/02 Officials willing to rethink plans to rebuild.
• 07/30/02 ENR Call for diversity at Ground Zero.
• 07/30/02 The Boston Globe reported that officials have put off further decisions on rebuilding until after November's gubernatorial election and that two business leaders say redevelopment officials are also seriously discussing the idea of buying out Larry Silverstein. The full article may require a subscription.
• 07/30/02 More designers and more designs are sought for Lower Manhattan.
• 08/19/02 The World Trade Center Memorial web site.
• 08/19/02 ImagineNY - gathering ideas for Lower Manhattan.
• 08/19/02 As the first anniversary of the Sept. 11 tragedy approaches, plans for the World Trade Center site

are in disarray, tainted by criticism that they're boring and small-minded.
• 08/19/02 Boring. Dull. Mediocre. And that final blow at a recent public forum: "It looks like Albany."
• 08/19/02 Further Designs Are Sought in Rebuilding of Downtown.
• 08/19/02 Op-Ed article: Going back to the drawing board.
• 08/19/02 Op-Ed article: A New Downtown: More Ideas Wanted.
• 08/19/02 Plans for the rebuilding of Lower Manhattan expanded to encompass all of downtown.
• 08/19/02 CNN has received over 900 designs for the WTC site from its viewers. You can view all 900.
• 08/19/02 Denise Scott Brown comments, in an Op-Ed article on the future of downtown Manhattan.

Building Code Revisions

• 08/19/02 NYC begins discussions on revising its building code.
• 08/19/02 High Rise High Jinks: National Real Estate Investor comments on the building code discussions.

• 11/01/01 An ENR article that should have been linked from the first days. Massive Assault Doomed Towers Terrorist Attacks Brings Down World Trade Center (9/17/2001).
• 09/20/01 USA Today has an excellent graphic describing the structure and the collapse of the WTC Towers.
• 09/20/01 This article from the Chicago Tribune, is an excellent statement from a well respected structural engineer, R. Shankar Nair, former chairman of the Council on Tall Buildings and Urban Habitat on what could have been expected and what could not have been expected. I believe everyone should read his statement.
• 09/27/01 Link Corrected: 09/25/01 There are a number of other interactive links from the New York Times that start with the "Mapping the Surface" page and include a seismographic image of the collapse. (A free subscription may be needed for the NYT) and the New York Times has an article explaining the technology that produced the image.
• 10/02/01 Some excellent graphics not previously linked to this page from the San Francisco Chronicle show the size relationship of the airplane and the tower floor plane. Scan both forward and backward from this site for other informative graphics.
• 10/10/01 Les Robertson spoke publicly for the first time this past weekend at the Manchester, NH meeting of the National Council of Structural Engineers Associations. The Wall Street Journal reported on his presentation as did Chris Hewitt, one of the Penn State AE students in attendance.
• 10/10/01 A semi technical article discussing some approaches to high rise building design approaches from the Wall Street Journal.
• 10/03/01 The New York Times of September 18 published an article discussing the fire response of the WTC that, in my view had some misinformation so I had not previously linked it. I have recently received a response letter to the editor form Manny Herrera, a Fire Protection Consultant so I have included both. Be sure to read Mr. Herrera's response regarding how a concrete building might have performed.
• 10/18/01 An excellent article written by G. Charles Clifton, a structural engineer with HERA presents what is perhaps a new perspective on the collapse. This article is well worth reading. (*.pdf format)
• Jon Magnusson, chairman-CEO of Seattle based Skilling Ward Magnusson Barkshire Inc., one of the successor firms to the engineer of record for the World Trade Center, Skilling Helle Christiansen and Robertson comments on just how good the structural system of the WTC towers really performed. (Taken from ENR)
• Data on the Boeing 757, size etc. is taken from the Washington Post.
• USA Today Time-line of the attack and the period afterward.
• Engineering News Record (ENR) (9/11/01) web site has some opinions. (I am not sure that the Penn Staters will agree with all that they say here. (LFG))
• CNN Chat with Tod Rittenhouse of Weidlinger Associates with some clear discussions.
• 10/18/01 One month after the attack on the World Trade Center, A panel of Boston area-based civil and structural engineers convened at M.I.T. to discuss the fate of the superskyscrapers. One member of that panel was Robert McNamara, PSU AE '63.
• 10/18/01 Engineers from M.I.T. provide their input in this article from ChicagoLandConstruction.com
• 11/28/01 A Scientific American article reporting on the MIT meeting.
• 11/28/01 MIT Technology Review also reports on the collapse. This is not a new article, just newly listed here with old information. It contains links to other MIT faculty opinions on the collapse.
• 10/29/01 Although not actually a discussion of an analysis of the collapse, this video clip of a news report from the SEAOC 2001 San Diego Convention is interesting. <RealMedia> < WindowsMedia>
• 10/30/01 The October issue of STRUCTURE magazine has two articles on the WTC. The Cover(*.pdf) shows an impressive view of the wreckage while one article (*.pdf). by W. Gene Corley, discusses the search for answers to the structural response. (The second article (*.pdf) is linked here and below.)
• 11/08/01 Jon Magnusson, Chairman and CEO of Skilling Ward Magnusson Birkshire Inc. published an editorial (*.pdf) in the October issue of STRUCTURE.
• 11/12/01 Some of the information being gathered by the ASCE/SEI investigation team and, their tentative conclusions, are now being made public. This NYT article "Why Trade Center Towers Stood, Then Fell" provides an up to date the review of what these experts now believe.
• 11/19/01 An excellent article from the November 19, 2001 issue of the New Yorker magazine discusses the World Trade Center, its structural concepts, the designers, the collapse and the investigation. This is one of the must read articles.
• 11/30/01 Although many have known for some time that WTC 7 contained large amounts of diesel fuel, I believe this is the first article to bring the collapse of WTC and its suspected cause to the forefront.
• 12/05/01 US News and World Report attempt to describe the collapse through graphics.
• 12/06/01 Using CAD simulation tools from automotive crash study techniques to simulate an aircraft smashing into buildings.
• 12/07/01 The Chicago Tribune article quoting Gene Corley, had of the ASCE Investigating Team, discussing the current theories of the collapse of the towers.
• 12/10/01 The graphics accompanying the Chicago Tribune article about the investigation provides some insights into the construction of the WTC and the theories of the collapse.
• 12/12/01 An ENR editorial warns about drawing premature conclusions and changes in future codes as a reaction to the WTC collapse.
• 12/13/01 An expert in fire protection has said that inadequate or faulty fireproofing that had gone unrepaired for years may have played a role in the failure of the two 110-story buildings.
• 12/13/01 An AP article on the role of the fireproofing in the collapse.
• 01/09/02 According to the NYTimes, NYC had been warned of the danger of the location of the fuel tanks at WTC 7
• 01/09/02 on Dec. 20, 2001, USA Today reviewed the events of Sept. 11 from the perspective a 3 months distance and reveals some of the more accurate information on what happened, how many lives were lost and how the evacuation progressed. This page also includes an interesting interactive graphic link describing the losses.
• 01/16/02 Richard Gewain, a member of the federally designated panel of engineers probing the collapses of the WTC Towers said "Conceivably, the building would have collapsed without the fire."
• 01/18/02 An excerpt from Construct in Steel (*.pdf) Vol 14, N3, September 2001 by the Australian Institute of Steel Construction.
• 02/11/02 CBS announced yesterday that it would broadcast a two-hour documentary special on March 10 culled from the videotape footage shot inside the World Trade Center by two young French filmmakers during the terrorist attack on Sept. 11.
• 03/04/02 Robert DeNiro will host "9/11" the exclusive insider's account of the World Trade Center attack from French filmmakers Gedeon and Jules Naudet. DeNiro is a prominent actor, director and producer living in New York City and is a co-founder of the Tribeca Film Center which is located just a few city blocks from ground zero.
• 03/16/02 The CBS documentary "Experiencing 9/11 from the Inside"
• 03/16/02 Firefighters comment on the CBS documentary.
• 02/12/02 The New York Times presents a "A Wounded City" - A Photographers Journal with commentary and photographs from some 7 of their photojournalists. You may click on the images as the audio is being played.
• 02/12/02 The year in pictures - AFTER Sept 11, 2001, from the New York Times.
• 02/12/02 360 degree views of NYC before and after Sept. 11.
• 03/04/02 Two studies try to establish speed of jets as they hit the WTC towers.
• 03/04/02 The National Transportation Safety Board has released none of the techincal information related to the Sept. 11 crashes.
• 04/16/02 Les Robertson reflects on the rise and fall of the World Trade Center towers. From The Bridge, a publication of the National Academy of Engineering. The previous link does not include the figures. The full volume of the journal. with figures is available as a *.pdf download.
• 05/15/02 HBO begins the editing of its special, narrated by former Mayor Rudolph W. Giuliani, "In Memoriam: New York City, 9/11/01" to be aired May 26 at 9 p.m.
• 05/29/02 Review of HBO special.
• 05/29/02 Elevator machinery protected one exit stairway and saved 16 people.
• 05/29/02 USAToday graphic showing how elevator equipment protected one stairway.
• 05/30/02 Fighting to Live as the Towers Died is a haunting chronicle of the last 102 minutes before the towers fell, built on scores of phone conversations, email and voice messages. The site also includes an interactive presentation inside the towers and a chronology of the events of September 11.
• 05/30/02 Accounts from the North Tower and the South Tower.
• 07/24/02 The events of 9/11 exposed deadly flaws in rescue plans. This page includes several interactive graphics showing locations of Police and Fire Department activity prior to collapse, audio of the emergency dispatches, and locations of units which suffered losses.
• 07/24/02 Disaster planner points to lessons learned.
• 07/24/02 The NOVA companion web site to "Why the Towers Fell."
• 08/30/02 The AIA has a DVD of the NOVA program available for rental.
• 08/19/02 Lost voices of Firefighters - some reached much higher floors than previously thought.
• 08/19/02 New York's firefighters were hindered by a series of failures in their response to the attack.
• 08/26/02 An older article on the squabbles between police and firefighters.
• 10/26/02 Report in NYT on claim by Charles Thornton that Petronas Towers would have withstood the terrorist attach.
• 10/26/02 Expert Report disputes ASCE/FEMA report conclusions on cause of collapse of Twin Towers.
• 10/24/02 Press Release issued by Silverstein Properties on further studies that they had conducted on the WTC collapses and its results
• 10/26/02 NYT article making a comparison between the WTC and Petronas Towers. Makes some good points and questions any conclusion that Petronas would have withstood the attach any better than WTC.

Building condition around WTC site

• There are many false rumors about the condition of other buildings in the area of the Twin Towers. "In fact, there is no evidence to support all the various speculation, such as rumors that 1 Liberty Plaza or the American Express tower could come down, which is definitely not true." according to Richard Tomasetti. A good summary of some of the buildings conditions is provided by the New York Times.
• 09/24/01: 09/20/01 -09/19/01 A map indicating the status of the buildings around ground zero. I do not know the source so I can not attest to the structural engineering accuracy of this information but at least it is a good representation of the location.
• 09/21/01 Buildings.com has a listing of the square footage of space destroyed or damaged in lower Manhattan. There is no indication that this summary has been coordinated with the professionally conducted structural assessments but it still provides some perspective to the problem.
• 09/24/01 The Washington Post has a fine diagram of the underground condition around Ground Zero, as of Sept. 21, 2001
• 09/25/01 09/24/01 Light Detecting and Ranging used to measure the rubble as reported by CNN. The same image, with some interactive views of the site before the attack is available from the New York Times. (A free subscription may be needed for the NYT)
• 09/27/01 added link: 09/24/01 CNN.com has an excellent 3-D graphic of the status of buildings in lower Manhattan.
• 09/28/01 ENR reports in its Sept. 24 cover story that most surrounding buildings are safe.
• 10/08/01 The Structural Engineers Association of New York has a map and list of assessed buildings as of September 22, 200. You may also go directly to their web page.
• 10/08/01 Preservationists say most of the 67 city landmarks below Chambers Street emerged ash-laden but unscathed from the attack. But they want to assess several buildings close to the collapsed towers, where access is still limited.
• 10/05/01 27.5 Million square feet of Commercial Office Space Believed Destroyed or Damaged in Lower Manhattan. As reported by Buildings.com on Sept. 14.
• 10/05/01 Four Percent of Manhattan's Total Office Space Was Destroyed in the World Trade Center Attack as reported by Buildings.com
• 10/18/01 One Liberty Plaza is scheduled to reopen on Oct. 22 with a ribbon cutting ceremony. There had been many rumors that the building was in danger of collapse.
• 11/30/01 Verizon has nearly all of the voice circuits knocked out by the WTC attacks restored and is now planning the rebuilding of its system.
• 11/30/01 The reopening of three subway stations damaged by the destruction of the World Trade Center is at least three years away, a chief engineer at New York City Transit said.
• 12/05/01 December 4 update on the condition of 90 West Street with reference to a few others. This classic building performed admirable even though many levels of spandrel beams were distorted in the collapse of the WTC.
• 12/06/01 The graphics with the above NYT article provided a view of the physical relationship of 90 West Street to the other buildings. Go to the "Fireprofing" tab for a comparison of the fireproofing systems for 7 WTC and 90 West St.
• 12/06/01 This article discusses the retail situation in lower Manhattan.
• 12/06/01 ENR reports that NYC is ready to give back to their owners some of the buildings compromised by the Sept. 11 attack.
• 01/09/02 As of December 19, ABC reports that the fires at the WTC site are finally out.
• 01/09/02 NYC has started to build viewing platform around the WTC site to accommodate the publics desire to see ground zero.
• 01/16/02 The Winter Garden looks to a rebirth through its restoration. This includes a very fine graphic.
• 01/16/02 Plans to rebuild WTC 7 with tentative ground breaking set for September 11, 2002.
• 02/11/02 The World Trade Center station of the E subway line reopened Monday, January 28 for the first time since Sept. 11.
• 02/11/02 The most extraordinary thing about the recently reopened World Trade Center subway station is how hauntingly ordinary it can look.
• 02/11/02 The Ritz-Carlton, New York Battery Park hotel plans to open.
• 02/11/02 Parents and teachers at Public School 89, which was evacuated after the terrorist attack of Sept. 11, have voted by a wide margin to return to their school on Feb. 28.
• 02/11/02 While redevelopment of the World Trade Center site is scheduled to begin soon, other involved groups fear the effort may be rushed.
• 02/11/02 For a while on Monday, February 4, office workers near ground zero could entertain the illusion that life was back to normal at the World Financial Center.
• 02/11/02 SouthWest NY in 2 World Financial Center, which was damaged on Sept. 11, has reopened.
• 02/12/02 At least 22 of the 45 buildings seriously damaged on Sept. 11 remain closed.
• 03/04/02 The tenants of 125 Cedar Street, one block south of ground zero, are excited and fearful to return home.
• 03/04/02 Public School 89 students arriving at their school for the first time since the September attack were mostly jubilant.
• 03/23/02 The steel began going up into the ravaged eastern facade of the Winter Garden of the World Financial Center.
• 04/22/02 Redesign of the eastern facade of the Winter Garden has been released.
• 04/16/02 St. Paul's Chapel on Broadway at Wall Street closed its doors to the public and opened them to the firefighters, police and other workers at the nearby World Trade Center site. Staffed by volunteers, the chapel has provided food and refuge around the clock ever since.
• 04/16/02 Within a few weeks, clean-up of the exteriors of many of the buildings around the WTC site will begin.
• 04/18/02 I had not seen much written about St. Nicholas Greek Orthodox Church previously. The tiny church building was crushed on September 11. Rebuilding Wall Street, (*.pdf) April 17, 2002 issue has an article about the church and the future the parishioners hope to rebuild.
• 04/18/02 The Greek Orthodox Archdiocese Of America reports on St. Nicholas Greek Orthodox Church, 155 Cedar St., NY, NY.
• 04/18/02 The St. Nicholas Greek Orthodox Church web site includes photos of the church as well as the site after Sept. 11.
• 04/18/02 Photographs of St. Nicholas Greek Orthodox Church in the shadow of the WTC.
• 04/18/02 Wall Street Journal article with map showing location of St. Nicholas Greek Orthodox Church and the New York Time published a brief article.
• 04/18/02 This article on St. Nicholas is essentially the same as those above. It includes a photograph of the collapsing towers behind St. Peter's Roman Catholic Church which is uptown from the World Trade Center on Church Street.
• 05/30/02 Bankers Trust Building at 130 Liberty Street remains deserted but still a tribute to the structural strength of this ordinary office building.
• 06/10/02 Victim's remains found in the clean-up of buildings surrounding Ground Zero.
• 06/21/02 The rebuilding of the Winter Garden continues, It may be that this provides a memorial to those lost at Ground Zero without all the turmoil taking place surrounding an "official" memorial.
• 07/08/02 No remains found in Deutsche Bank building across from WTC site.

WTC Below grade conditions

• 09/18/01 The New York Times has published an extensive article on the foundation of the entire World Trade Center complex basement structure, reporting on input from George J. Tamaro, a staff engineer for the Port Authority in 1967, when he helped build the World Trade Center's basement, a 16 acre, 70 foot deep hole in the ground.
• 09/26/01 Concern has been expressed over the stability of the "bathtub" substructure of the WTC as the debris are removed. Two firms have been hired to guide the demolition and subgrade consideration as reported by ENR.
• 10/08/01 Visual surveys indicate roughly 50% of the seven-level "bathtub" basement structure of the World Trade Center is now rubble as a result of the impact of the collapse of the twin 110-story towers, from ENR 10/08/01.
• 10/08/01 Along with the basement structures, the subways have sustained significant damage. Access is now showing the extent of the needed repairs there.
• 10/01/01 New York Times article with graphic on what it will take to rebuild the subways under the WTC.
• 10/10/01 The basement structure gets further assessment as reported in this New York Times article.
• 10/25/01 The process of stabilization of the "bathtub" has begun according to ENR.
• 11/01/01 Two of the NYC Subway lines are set to reopen well on advance of their anticipated date.
• 11/02/01 The extensive underground mall area is now slowly being reached. Millions of Dollars of gold and silver are safe in a massive vault.
• 11/19/01 About 40 of the estimated 1100 tiebacks needed to complete the cleanup of the WTC site have been installed in recent weeks.
• 12/05/01 As the clean up continues in depth focus is being directed to the "bathtub" foundation.
• 01/09/02 Subway line damaged in attack may reopen much earlier than originally anticipated, according to Jan 4, 2002 NYT.
• 02/11/02 Damage to the underground wall that helps hold back the Hudson River at the World Trade Center site has city officials considering the installation of a new concrete wall, a large job given the enormous size of the so-

called bathtub.
• 03/16/02 Sections of the "bathtub" collapse.
• 03/23/02 Workers are hurrying to shore up and patch a 90-foot-wide gash in the bathtub.
• 04/16/02 The engineer who oversaw the construction of the World Trade Center "bathtub" describes the recovery efforts. From The Bridge, a publication of the National Academy of Engineering. The previous link does not include the figures. The full volume of the journal. with figures is available as a *.pdf download.
• 05/16/02 Photos showing the condition of the PATH tunnels between Exchange Place in New Jersey and the WTC as well as some photos of the "Bathtub" clean-up.

WTC site clean-up

• The clean up that now must take place in both NYC and Washington will involve many from our industry. The Structural Engineers Association of New York under the direction of Thornton-Tomasetti is coordinating the structural engineers. Kyle Krall PSU AE '87 form the NYC firm of is one of the PSU AE's who is closely involved in those efforts. He provides the following report on Saturday Sept. 15. Kyle had previously submitted a report on Sept. 12.
• 09/24/01 Christopher Cerino, PSUAE '95, Project Manager for DeSimone Consulting Engineers, P.L.L.C., NYC is working on site to help the demolition teams in the clean-up. He has provides some thoughts.
• 01/11/02 Chris Cerino has provided an update on his firms activities at Ground Zero along with some interesting photos.
• 09/28/01 As the removal of debris continues, a plan is emerging to conduct the massive effort as reported in the Oct. 1 issue of ENR.
• 10/17/01 Timothy Schenck, a structural engineer with HLW International, LLP, NYC, and former CE graduate student, sent an excellent email to Dr. Jeff Laman detailing his involvement at the site, along with some interesting photos.
• 10/18/01 This article on the cleanup also discusses how the buildings fell. This should be read with some skepticism at this point in time.
• 10/23/01 President Bush Proposes $6.3 Billion for New York City, $925 Million to Rebuild Pentagon
• 10/23/01 While the structural investigating teams search for information on just how the towers collapsed, others are "Sifting Mountains of Debris for Slivers of Solace."
• 10/30/01 The October issue of STRUCTURE magazine has two articles on the WTC. The Cover(*.pdf) shows an impressive view of the wreckage while one articlle (*.pdf) by James Stefano discusses the involvement of the engineering community in the cleanup. (The second article (*.pdf) is linked here and above)
• 11/12/01 A report from October 25 indicating that Turner expects to be finished with the WTC 7 cleanup by some time in November.
• 11/12/01 ENR reports that New York City officials managing cleanup of the World Trade Center are asserting more control of the disaster site and expediting operations by limiting the number of police and fire personnel handling victim recovery operations.
• 11/12/01 Safety at Ground Zero has always been a concern but the NYT reports that it is a growing concern as the cleanup progresses.
• 11/19/01 ENR reports that New York City could soon be turning to San Francisco-based Bechtel Group Inc. to manage the estimated $2.5-billion cleanup of the World Trade Center site.
• 11/19/01 The fire that continues to burn at the WTC site is said to be the longest commercial building fire in United States history.
• 12/17/01 The last remaining piece of standing wall of the WTC towers cam down Saturday, December 15.
• 01/09/02 The clean-up takes on an new dimension as the ongoing project moves into its 4th month.
• 01/16/02 ENR Reports that Bovis takes lead at WTC cleanup, as subway repair fast-tracks.
• 01/16/02 Cleanup moves below grade where the challenges are even greater.
• 01/16/02 NYTimes discussion of the enormity of the cleanup effort.
• 01/16/02 The viewing platform at ground zero generates a great deal of interest as well as concern.
• 01/18/02 Will the huge financial risks contractors cleaning up at ground zero have assumed make it hard for them to get bonded for other construction projects as they continue to work without insurance.
• 01/22/02 Milton Steel, Milton, PA (Vel Holcombe AE '64 and Chris Holcombe, AE '90) is supplying steel for a bridge to be used in the clean up at ground zero as reported in the Daily Item.
• 01/24/02 The NY Times reports that the clean up is moving quickly at Ground Zero.
• 03/04/02 Analyses of air quality near the site of the World Trade Center collapse have produced some encouraging findings.
• 03/04/02 Confusion over the air quality inside and outside buildings near ground zero was clearly evident again yesterday at an investigative hearing before the national ombudsman for the federal Environmental Protection Agency.
• 03/16/02 Crews are Rushing to Restore WTC's Hard-Hit Infrastructure.
• 03/16/02 New funds are being made available to push the rebuilding of NY infrastructure.
• 03/18/02 The end is near in the cleanup at Ground Zero.
• 03/28/02 As cleanup moves to a conclusion, the NYFD is using satellite data to record the location of effects in an attempt to provide data that may help engineers understand how the towers collapsed.
• 04/16/02 The source of the famous WTC Flag is confirmed.
• 04/30/02 ENR Award of Excellence Winner: Michael Burton - Creating order from chaos in leading the public-private construction team that responded to the Sept. 11 devastation at Ground Zero.
• 05/15/02 The clean-up task is nearly done.
• 05/15/02 Recovery winding down at Ground Zero.
• 05/15/02 Sifting the last tons of debris.
• 05/15/02 Testing of the air after Sept. 11 continues. Whether there will be any continuing impact is still to be seen.
• 05/16/02 MSNBC reports that Federal and city environmental officials have announced they would pay for professional cleaning and air-quality testing of the apartment of any area resident who requests the work.
• 05/29/02 Clean-up and recovery to conclude.
• 05/29/02 WTC cleanup to end with May 30 ceremony.
• 05/29/02 Details of the ceremony to end the clean-up at Ground Zero and some of the controversy.
• 05/30/02 Tha last column, No. 1,001 B of 2 WTC, has come down.
• 05/31/02 Last emergency cable removed in WTC area
• 05/31/02 The final elements have been removed and the site is now silent.
• 06/21/02 An ENR summary of the winding down of the clean-up at ground zero
• 06/21/02 Clean-up draws to an end as the Fresh Kills landfill is almost as empty as Ground Zero.
• 07/08/02 The clean-up has been completed
• 07/08/02 William Langewiesche is the author of "American Ground: Unbuilding the World Trade Center," on life at the World Trade Center site after the towers fell. It is a comprehensive look at the inner workings of the World Trade Center cleanup effort—and the longest piece of original reporting The Atlantic has ever published. "American Ground" will be published in book form by North Point Press (a division of Farrar, Straus & Giroux) in October.

Occupancy of the WTC

• 09/18/01 The Dallas News has a WTC graphics with a listing of the companies that occupied the various floors.
• 09/18/01 The American Society of Civil Engineers has a list of the engineering related firms located in the Twin Towers and the number of that societies members and status for each company.
• 09/24/01 The New York Times has a great deal of information on line, some may require completing a free subscription. This link is the best I have seen at showing which firms occupied specific floors and the status of their people as of Sept. 16. Both the north and south towers can be viewed.
• 10/01/01 The Wall Street Journal listing of companies that occupied the twin towers and the status of their employees, updated regularly.
• 10/08/01 Architectural firm, Mancini Duffy, with 140 employees in the World Trade Center, survived unscathed and were back to work in three days
• 11/07/01 The November 4, 2001 New York Times has reported that a Secret C.I.A. Site in New York Was Destroyed on Sept. 11.
• 07/24/02 Companies who lost employees in the WTC have begun to put together career profiles of the employees to assist families in securing financial support based on future earning potential.
• 08/21/02 With the New York City medical examiner office's release on Monday of the most thorough list of victims, it is possible to chart the devastation by ZIP code. Be sure to check out the interactive mapping of location by zip code of victims homes linked on the right side of the page.
• 08/28/02 7 Missing Since Attacks Found Alive.

Structural Investigation Teams

• An ENR review (9/13/01) of the firms that are beginning the investigation/assessment of the remaining buildings. You will note that PSUAE has strong connections with all of these firms. Most of the names mentioned are known personally by the AE faculty.
• 09/18/01 ASCE held a media briefing on Friday, Sept. 14. The principle investigators of the teams ASCE recently established to study the devastation held a live telephone Media Briefing. The team leaders appealed to the media for still photos and video footage to aid in their investigation. They also discussed the procedure they will take for the study which will later be published and released to the public. You may hear the briefing or read the transcript at this site.
• AISC is establishing a task force to study the WTC collapses.
• The Structural Engineers Association has provided some structurally pertinent facts in a message received by the Penn State AE Structural Engineers Association student organization.
• Press Release from the Structural Engineers Association of New York in MS WORD format. Among other things they lay to rest the rumor about 1 Liberty Plaza. The current President of SEAoNY is W. Richard Mahoney, PSUAE ' 71 <mgmclaren@mgmclaren.com >
• The North Jersey Branch of ASCE is collecting names of volunteers.
• 10/03/01 The National Science Foundation has funded some projects related to the Attack on America.
• 10/08/01 Dr. Abolhassan Astaneh-Asl, professor at the University of California at Berkeley and Ph.D. advisor of Dr. Judy Liu PSUAE '95, has reported, from preliminary results of his investigation at the WTC site, that the buildings withstood the impacts of the planes.
• 10/08/01 A better report of this information came from the Associated Press.
• 10/19/01 Prof. Astaneh-Asl, although no longer a part of the ASCE lead team, conducted an interview on National Public Radio, covering his assessment of the collapse of the WTC.
• 10/25/01 A very good article on the forensic investigation of the WTC collapse from Architecture Week.
• 10/29/01 The President of SEAoNY has asked for volunteers to help identify steel as to location within the WTC towers before any of it gets sent to recycling. This article also discusses other new aspects of the cleanup.
• 11/01/01 Edward M. DePaola, president of the Structural Engineers Association of New York (SEAoNY) issued a call for volunteers to form a rotation at the two scrap yards in New Jersey receiving steel from the World Trade Center's twin 110-story towers. All of the steel in the Towers was marked during construction as to its location in the building. This information is allowing the cleanup and investigation teams to identify which floor where each piece of steel came form.
• 12/05/01 Again, Prof. Astaneh-Asl has given an interview, this time to the Chronicle of Higher Education. The value in this article is in the information gleaned from the other interviews with members of the ASCE Team.
• 12/05/01 Academic teams using high-tech methods to assist in the WTC investigation are reported on in the Chronicle of Higher Education.
• 12/17/01 An assistant professor of fire science at John Jay College of Criminal Justice criticizes the ASCE/FEMA investigation.
• 12/18/01 The National Science Foundation World Trade Center information site.
• 01/09/02 Some are calling for a broader inquiry into why the Twin Towers collapsed, including the two Senators form NY.
• 01/16/02 Another general article from the Associated Press on the investigating team.
• 01/18/02 The National Institute of Standards and Technology will conduct its own study to supplement the ASCE/FEMA sponsored teams study.
• 02/11/02 A February 2, 2002 report on some aspects of the ongoing investigation.
• 03/04/02 The FEMA/ASCE team report indicates that the diesel fuel in WTC 7 was instrumental in the buildings collapse.
• 03/04/02 Widows and other survivors, as well as a number of engineers and fire safety experts, insist the FEMA/ASCE investigation into the WTC collapse is insufficient and intend to ask Congress to expand the inquiry.
• 03/16/02 The head of NIST calls for new standards in testimony before Congress.
• 03/16/02 Lawmakers continue to discuss the WTC investigation and what future changes may need to be made in rules for skyscrapers.
• 03/16/02 The complete statement of Dr. Arden L. Bement, Jr. Director, National Institute of Standards and Technology, United States Department of Commerce before the Committee on Science, House of Representatives, United States Congress. “Learning from 9/11: Understanding the Collapse of the World Trade Center”
• 03/16/02 Another analysis of the statements of Arden Bement.
• 03/16/02 It would take $40 million to adequately study the performance of the collapsed twin, 110-story towers of the World Trade Center and surrounding buildings damaged by the Sept. 11 terrorist attacks, said W. Gene Corley, in testimony March 5, in Washington, D.C., before the House Science Committee.
• 03/16/02 No Tower Can Withstand Attack as Jets Get Bigger, Expert Says, reports on a presentation made by Les Robertson.
• 03/19/02 Royal Institute of British Architects initiates a fire study in response ot the WTC tragedy.
• 04/18/02 Engineers monitoring the scrap from the collapsed WTC have identified a piece that came from floors 100-103 of tower one.
• 04/16/02 As fire protection undergoes close scrutiny, there are questions raised about the standard fire tests used in current practice to establish building fire ratings.
• 05/15/02 Draft legislation unveiled May 1 before the House Science Committee would give the National Institute of Standards and Technology the lead role in disaster investigations.
• 05/15/02 Wider Inquiry Into Towers Is Proposed and NIST to lead.
• 05/15/02 W.Gene Corley, Ph.D., P.E., S.E., team lead for the ASCE/FEMA World Trade Center building performance study team presented these remarks at a press conference on the introduction of "National Construction Safety Team Act."
• 05/15/02 The House Committee on Science legislation on follow-up investigation.

Pentagon site

• 09/26/01 09/24/01The Pentagon has not received as much attention as the Twin Towers for obvious reasons. This Washington Post graphic shows the size of the building and the size of the aircraft to scale, as well as discussing the rebuilding of the Pentagon. In addition, the site has links to other graphics of interest.
• 09/24/01 The extent of the structural damage to the Pentagon is shown as well as the location of the Navy command center.
• Structure Magazine had published an article on the retrofitting of the Pentagon that may be of interest. It is in a pdf format.
• 09/26/01 The Pentagon Renovation Office has hired two firms to guide the restoration of the damaged portion of the Pentagon as reported by ENR.
• 10/02/01 Some excellent graphics relating to the Pentagon from the San Francisco Chronicle. Scan both forward from this site for other informative graphics on the Pentagon and backward for the World Trade Center.
• 10/04/01 Reagan National Airport reopened Oct. 4. The changes at the terminal and on the flight path are illustrated in this Washington Post graphic.
• 10/08/01 The Pentagon rebuilding process moves ahead. It will include a memorial to those who lost their lives in the attack.
• 10/10/01 Continued assessment of the movement of the Pentagon structure.
• 10/23/01 Structural Shift In Pentagon Could Accelerate Demolition
• 10/23/01 Shifts In Structure Are Seen As Pentagon Demolition Begins.
• 01/09/02 The AP reports on the costs of the Pentagon rebuilding.
• 01/09/02 The Pentagon is concentrating on rebuilding both he structure and the lives. This article talks about some of the people who are beginning their own recovery.
• 01/21/02 One of many NYTimes graphics. This one shows the rebuilding of the Pentagon.
• 01/21/02 Space Imaging presents a gallery of Pentagon photos from space. (This site also includes WTC photos)
• 02/11/02 Pentagon Crews Making Good On High-Profile, Fast-Track Schedule
• 04/30/02 Progress on rebuildingthe Pentagon.
• 05/29/02 Planning for Pentagin Memorial
• 06/03/02 Companies cooperate with the rebuilding of the Pentagon.
• 06/21/02 Pentagon Memorial design guidelines announced.
• 06/21/02 The final stone is placed in the Pentagon exterior.
• 06/21/02 Soldiers Online reports on the aftermath of Sept 11 at the Pentagon.
• 07/30/02 National Geographic reports on the concrete material autopsy for the Pentagon.
• 08/26/02 1,600 sign up for Pentagon memorial competition.
• 08/29/02 Victory! Pentagon Team Beats The Odds On One-Year Rebuild.
• 08/30/02 Thousands of people from across the nation and around the globe have applied to enter the design competition for a Sept. 11 monument near the Pentagon.
• 09/02/02 Engineering News Record: Commemorating: 9/11/01- 9/11/02 Part One - Washington D.C. including a picture gallery.
• 01/20/02 The Pentagon Report has finally been released. It is available from ASCE.

In Memoriam - Penn State

• 01/10/02 Penn State has now confirmed that 10 Penn Staters lost their lives as a result of the September 11 events, 3 were from the College of Engineering. Linked information is from the Center Daily Times of October 2, and October 15, 2001 and The Penn Stater of January/February 2002.
• 10/30/01 update:10/25/01 update: 10/08/01: 09/24/01: 09/20/01: 09/19/01: Michael Eskra PSUAE '00 of Flack + Kurtz in NYC sent a brief email to Prof. Ling. His NYC roommate Dave Suarez (IE '99) is missing. Mike as sent an update with a note about the memorial service for Dave and I have received an email from Deloitte Consulting, including Dave's obituary and have just received a photo of Dave. An article from the Center Daily Times has been added. On 10/25/01 I have added information on two scholarships that have been set up in Dave's honor. These provide a most fitting way for any of you who knew Dave to honor him and to express to Mike your sorrow at the loss of his friend. 10/30/01 The NYT Portraits of Grief profiled Dave on October 26.
• 11/12/01 Mike Eskra has set up a web pagehonoring Dave Suarez that all of Mike's and Dave's friends should visit.
• 01/16/02 The Penn State Alumni Association has provided a brief write-up on each of the Penn Staters lost (*.pdf) on September 11, 2001.
• 05/09/02 The Penn State Intercom reports on the status of scholarships honoring Kermit C. Anderson and David Suarez

• A first-hand report comments from Lynda Tollner PSUAE '84 who was on the concourse level when the first plane hit.
• Another first hand report from Kenny Pliska PSUAE '85 who was on his way to work.
• Valerie Gillespie PSUAE '85 tells the harrowing story of her mothers escape from the debris.
• Michael Ajomale PSUAE '01 was to start work Wednesday in NYC.
• Greg Flinn, PSU Finance '96 writes about the ferry trip toward the city.
• 09/18/01 Rebecca Kennedy PSUAE '98 works in the West Village but saw the first plane hit the North Tower.
• 09/21/01 Lee Hanel PSUAE '99 works about 30 blocks from the area but has provided her perspective in a note to Nancy Witherite in the Assistant Deans Office.
• 09/18/01 One of the engineering firms located in the the towers was American Bureau of Shipping. They were on the 91st floor of the North Tower. Although these folks are not Penn Staters, their story should be shared. It is provided by a friend of Prof. Mistrick who used to work for this company. The good news is that all 11 employees got out.
• 09/27/01 David Kravette, a managing director of Cantor Fitzgerald comments on his view from the lobby of the North Tower and the free falling elevators and the fire ball at the lower levels of the tower.
• 10/01/01 Notes from Robert Ivy, FAIA, Editor-in-chief of Architectural Record. He writes "A number of you have asked what happened in the intervening days after the tragedy. Here is what I can report in a piecemeal and highly personal manner: "
• 10/10/01 This article tells of escaping from an elevator, stuck at the 50th floor. It is particularly interesting, from an engineering point of view, as it describes the construction of the walls of the elevator shaft.
• 12/10/01 Staff of the Wall Street Journal Online News Room recall the events of Sept. 11 in an extensive article. There are also links to other firsthand reports.
• 01/24/02 Staff of National Public Radio discuss that organizations response to the events of September 11.
• 03/19/02 Dennis Smith, an 18-year veteran of the New York City Fire Department, sets out to describe the attack on the World Trade Center and the heroic rescue efforts that ensued in Lower Manhattan.
• 08/21/02 Al Masetti worked in Tower One. His story about one of the victims as well as his thoughts based on being in one of the stair towers during the event are quite insightful.

• 09/19/01 Lanty Butchko PSUAE '95 has provided what I believe to be the complete update on the Southland Industries group at the Pentagon. He was not at the site but had worked there for two years. He reports that Shawn Cingle PSUAE '00 was on site in our trailer at the time of the crash, located within about 100 yards of the building on the opposite side of the crash. He and 4 of 4 Southland employees are safe and healthy. This, along with the report from Jess Kelley '98 AE, <JKelley@southlandind.com> that she was in San Francisco but that "the entire Southland Industries Pentagon Job site personnel are ok and accounted for" provides all I have on Southland.

Lanty indicated further that Southland is part of a design/build team that expects to be working on the renovation
of wedges 2-5 over the next 10 years. Tim Michael PSUAE '91 will have an instrumental role as our project manager. The crash affected part of the area that was 1st on that renovation schedule and we are currently unsure of how we may be involved in its repair.
• I received an message from David M. Rubando, a PSU '96 graduate from the Structural Design & Const. Engineering Tech. program at Penn State Harrisburg. David was in the Pentagon at the time of the attack.
• 09/18/01 Tom Forrest PSUIE '85 sent an email that he received from a close friend that had transferred to the Pentagon just before the attack. It doesn't quite describe the engineering point of view, but it does give a personal account from 3 windows to the right of the plane's impact.

• According to Judy Liu '95 AE (via Rick Burt '96), Chris Cerino '95 AE <CCerino@de-simone.com> is with DeSimone Chaplin & Dobryn in NYC. Both he and Jessica are doing OK, but he was stuck in the city last night.
• A second hand report from Jonathan Dougherty on class of '99 and '00 members.
• John Bechtel '92 <jbechtel@tcco.com> of Turner, currently located here in State College, reports that the 15 Turner employees from their field office located in one of the Twin Towers all got out safely. We do not know if there were any PSUAE's in that group.
• Steve Darr '75 <sdarr@hlw.com> reports that, given the situation here in NY, phone calls can sometimes be received. Getting a line out is sporadic due to the volume. Cell phones the same. Best to hold tight for a day or two. The city is quiet, almost empty. People are encouraged to stay home. General transportation by train is about the only means into the city. Subways run but since the biggest lines can't get passed WTC they are essentially useless. Many businesses are closed or on limited operations. No trucks, cars, taxis or buses - only ambulances with sirens wailing and an occasional fighter overhead. People are meandering along lost in thought, shock and/or both. An overriding calm is the immediate impression combined with an eerie quiet.
• I learned from his sister that Kyle Krall '87 <kKrall@lzagroup.com> with Thornton-Tomasetti was on the scene this morning Sept. 12, at 7:45 with other engineers and a police escort, to assess other structures in the area. Kyle then sent an update. See the ENR 9/13/01 link below.
• Sue Davis, PSUAE '92, <suebee_44@msn.com> editor ot Structural Engineer, sent this message: Hello everyone, I was writing my comment today for the October issue of Structural Engineer, and I felt compelled to include my true feelings about the tragedy and share them with my Christian friends, especially those that missed 7:22. In Christ, Sue
• In a message form Tiffany Houser PSUAE '98 <tiff242@hotmail.com> she says, we are all concerned about our friends in these cities. We have heard from Pat Chan, who worked in the city, and Tzy Chow (who we all know can be anywhere at any time!) I have heard from many people in the DC area - nothing but good news.
• Ian C. Schmellick PSUAE '98 <icschmellick@home.com> writes. Just to let you know. All Arup NY employees are safe and accounted for. Our office was unfortunate enough to see everything from beginning to end, but were fortunate enough to be out of harms way. David Jones, Kamesha Bell, Rebecca Kennedy (no longer at Arup, but safe and sound), and Myself are all ok. Brian Streby is still in the UK as far as I know, and OK. That covers our 1998 AE class that's here at Arup I believe. Amy Koerbel is OK as well, and so is Eric Balkey. Eric is down on site at Philly. I don't know their graduating years.

• 09/27/01 The Washington Post collection of photographs.
• 10/01/01 The Washington Post collection of audio and video clips.
• You have seen many pictures but this series of 6 show clearly the collapse of the twin towers. These photos came to us from Kevin Choi <KChoi@kpff-la.com> PSUAE '00 and were taken by someone at NBBJ.
• One of our 4th year students, Megan Hawk, < mdh192@psu.edu> provided this power point show of pictures form her sister, originally from a friend whose father worked on the 80th floor. He was not at work this day.
• Here is a web site of images... it has the 1 meter, finer resolution IKONOS images which have incredible detail considering they are taken from space. The page might take a while to load if you are on a slow computer.
• The Washington Post web page has a series of photos showing the impact and the collapse.
• Les Robertson, as the structural engineer for the World Trade Center has a number of pictures on his web page that are reminders of the grandeur that was the World Trade Center. His main web page also has a panoramic view.
• 09/27/01 Space Imaging has provided free images from space of both the WTC and Pentagon from space. The home page opens with an image of the WTC that flips from before to after.
• 10/23/01 These pictures were taken from the Goldman Sachs jotsite in Jersey City. They were taken by Kline Iron & Steel Co., the steel fabricator from Columbia, SC. and provided by Tom Ferrell of Ferrell Engineering, Inc. who furnished connection designs for the project. The are in a powerpoint presentation.
• 11/02/01 "Here Is New York" presents a gallery and on line exhibition of photographs relating to the events of September 9. Images are donated from amateurs and professionals. All images are available for sale for $25 with the net proceeds going to the Children's Aid Society WTC Relief Fund. This site includes the largest number ( I have viewed over 300) and greatest variety of images I have seen chronilcing the disastrous events of the day and the aftermath. It is well worth the time to view, even if you do not intend to purchase any prints.
• 11/07/01 I received a very detailed aerial (or space) view of ground zero that I have linked in two sizes, large (3701KB) and 25% (289KB). The smaller one gives significant detail but the larger one is quite impressive. I have not been able to identify the exact source for this but I do know that it came form the United Nations web site at some point.
• 11/13/01 The New York Times has an extensive collection of interactive graphics to explain aspects of both the WTC and Pentagon attacks and aftermath.
• 12/05/01 Laser Scanning Technology from the GeoSensing Systems Engineering group of the Department of Civil & Coastal Engineering at the University of Florida provide another interesting aerial image.
• 12/17/01 Trinity Church, Broadway at Wall Street, has a collection of photographs that chronicle the events from the perspective of a neighbor.
• 01/22/02 A collection of images on Terrorism and the the World Trade Center from Yahoo News.
• 01/22/02 Three photos by Jeff Mermelstein on the NY Times web site.
• 01/22/02 The New Yorker Magazine cartoonsrelating to the attacks and the environment in the aftermath.
• 03/04/02 The U.S.Army web page on the WTC disaster response has some amazing graphics and information.
• 04/16/02 The September 11 Photo Project
• 05/16/02 MSNBC slide show and video image collection is accessible for this page. Check link on page left.
• 05/29/02 A photographer approaches his photographs of Ground Zero as art.
• 07/19/04 Steve Spak has moved his photograhy sitre and has more Grouond Zero photos and books available.

• The South Tower (2 World Trade Center) collapsed first. A very clear photo of the initiation of the collapse was taken by Amy Sancetta of the AP. Note the tower tilting to the south.
• From a somewhat different direction, pictures 10 and 11 on the Washington Post web page show the South Tower begin to collapse with a tile southward and return back to somewhat level and then twist slightly clockwise.

WTC facts: Design and Construction

• 09/21/01 The American Iron and Steel institute published a pamphlet on the World Trade Center in approximately 1964. "Contemporary Steel Design," Vol. 1, No. 4. The publication is now available in pdf format. The files are very large so it could take a long time to download on a slow connection. Cover, 1-2, 3-4, 5-6, 7-8, 9-10.
• 09/28/01 Engineering News Record "125 years in ENR History" high lighted the World Trade Center twin towers in its 1999 series in which they discuss some of the special aspects of these buildings.
• 10/01/01 World Trade Center statistics from Architectural Record.
• 10/02/01 A post September 11 graphic of the world's tallest building as taken from the San Francisco Chronicle.
• The Chicago Tribune has a article that should be of interest. It addresses some design issues and has some pertinent comments from Les Robertson from a conference last week. And another article by the Architecture Critic of the Chicago Tribune.
• 09/25/01 The Twin Towers contained more than 200,000 tons of steel, 425,000 cubic yards of concrete and 600,000 square feet of glass in 43,000 windows. Another New York Times article discusses the dynamics of the collapse.
• 10/01/01 Architectural Record World Trade Center Site.
• 10/05/01 Since at least 1998, there has been significant disagreement over the definitions for the "World's Tallest Buildings." I received an interesting article from Structural Engineering International that I believe is from March 1998. Unfortunately the individual who sent it to me did not include the author information. It is still an interesting article.
• 10/08/01 Architectural Record article on history of World Trade Center.
• 10/18/01 Skyscrapers.com was listed on this site but it has been completely redesigned so it is worth noting again. It contains many photographs of the construction of the WTC towers as well as a great deal of information on the collapse and aftermath.
• 10/18/01 An article from Skyscraper.org about the original construction of the World Trade Center towers.
• 10/18/01 Concurrent with its "Skyscrapers: The New Millennium" exhibit in The Octagon, the American Architectural Foundation (AAF) is displaying in the adjacent AIA headquarters lobby the only original model of the World Trade Center known to be in existence.
• 11/01/01 GreatBuildings.com WTC web site with many great photographs.
• 11/01/01 The October 2001 issue of Structural Engineer included a brief structural history article (*.pdf) on the WTC.
• 11/01/01 Engineering News Record Cover and Feature articles from the past history of the World Trade Center.
• How Columns Will Be Designed for 110-Story Buildings (04/01/1964)
• Tall Towers Will Sit on Deep Foundations (07/09/1964)
• WORLD FINANCIAL CENTER - built on fill from the construction of the WTC - Megajob Takes Foothold In Fill - New York City's $1-billion river development survives snags (4/14/1983)
• Trade Center Digs Out After Blast (3/15/1993)
• Anatomy Of A Building Disaster (3/8/1993)
• 11/12/01 An interesting discussion from CITY Journal of the political aspects of the development of the WTC project from its original inspiration in the 1950's and the meaning for the reconstruction effort of NYC.
• 12/05/01 A short series of some early photos and facts of the WTC (As well as some Sept. 11 photos)
• 12/05/01 A profile of WTC Architect Minoru Yamasaki.
• 01/11/02 The National Building Museum is holding an exhibition honoring the WTC entitled "Twin Towers Remembered" through March 10, 2002.
• 02/11/02 "WTC: Monument," exhibit opens Tuesday February 5, 2002 at the New-York Historical Society, Central Park West and 77th Street.
• 02/11/02 The World Trade Center Towers in film.
• 03/18/02 Eric Darton published a book, in early 2000, called "Divided We Stand, A Biography of New York's World Trade Center". The result of eight years of research, writing and revision, it also distilled the cumulative associations of my 50 years as a New Yorker and witness to the city's heroic and deeply flawed trajectory of development. He is continuiong to add to the information through a web site that is quite interesting.
• 04/16/02 Seattle's IBM Building was the precursor for the World Trade Center. This article form the Puget Sound Business Journal talks a bit about IBM and WTC.
• 08/19/02 PBS Building Big WTC fact sheet web page.
• 08/19/02 Les Robertson lists the many "firsts" of the WTC.

• 09/25/01 Questions arose early about the insurance loss associated with the attack on the World Trade Center and whether the war-acts exclusion of most insurance policies would be invoked. This Sept. 24 Newsweek article discusses the estimated losses and also states that the insurance industry was not going to consider invoking the war-acts exclusion and that they had already begun writing checks.
• 10/04/01 The insurance industry appears to be handling the situation in a prompt and caring way.
• 10/23/01 Contractors and other construction industry officials had better start planning for bad news when they go to renew their insurance according to an article in the October 22 ENR.
• 10/23/01 The legal battles have begun as the leading insurer of the WTC sues to limit their coverage. This page also includes links to other insurance related NYT articles.
• 11/08/01 An email was received without attribution that indicates that billions of dollars of insurance to rebuild the World Trade Center could depend on a single e-mail.
• 11/12/01 Federal Government looks to limit insurance company liability for future terrorist attacks.
• 11/27/01 As time passes, less critical losses are identified. This article is an interesting assessment of the