Doug Dozier, Sara Holden, Bethany Drab, Matt Neustadter
Abstract
On the night of July 17th, 1981, hundreds people were gathered in the Hyatt Regency Hotel to participate in one of the traditional “tea dances.” Many were gathered on the dance floor, and the three various walkways suspended on the floors above. At 7:05pm, the fourth floor walkway collapsed, bringing down the second floor walkway with it. The walkways crashed to the floor, killing 114, and leaving 200 more injured. A flaw in the connection of the walkways and support rods was to blame, and the engineer who signed off on the design lost their licenses. The hotel was restored, and is currently functioning under normal conditions.
January 1978, construction began on the Hyatt Regency Hotel in Kansas City, Missouri (Baura 2006, 53). The design objective was to connect the bedrooms on one side of the hotel to the conference rooms using several different levels so as to dramatically enhance the interior space. A year later, during the construction phase, the design of the hanger rod connections was changed from a one-rod to a two-rod system. The fabricator (Havens Steel Company) received the drawings back stamped with G.C.E.’s review seal and constructed the walkways as directed. Later that same year, more than 2700 square feet of roof collapsed when one of the roof connections at the north side of the building failed. G.C.E has stated that they requested on-site representation on numerous occasions but their requests were not answered to due additional costs in on-site inspection. On the night of the collapse, the Hyatt Regency Hotel was hosting a tea-dance party in their atrium lobby (Texas A&M University 2009). The total number of people in attendance was estimated to be over 300 (Marshall 1982). Many of these party-goers were standing and dancing on the suspended walkways in the atrium just before the second and fourth floor walkways collapsed to the atrium floor (Texas A&M University 2009). Forty people were located on the second walkway, even though the upper bound for a single spanned occupancy is 16 (Marshall 1982). At 7:05pm, popping was heard up to 30 meters away as the final restraining nut ripped through the box beam (Nelson 2006).
Causes of the Collapse
The Hyatt Regency Hotel walkway collapse did not occur as a result of innovative design, construction or material use, but rather as a product of numerous management errors. It was these fatal management errors that resulted in the flawed construction detail to be used in the support system of the walkways of the Hotel Atrium (Moncarz, Fellow, and Taylor 2000). Various events and disputed communications between G.C.E. engineers and Havens Steel Company resulted in the design change from a single to a double hanger rod box beam connection on the fourth floor walkways (Texas A&M University 2009). The original design detail of continuous threading of the nut through two stories of the building appeared to be impractical to the contractor and as such he changed the design drawings (Shop Drawing 30 and Erection Drawing E-3) and replaced the original single hanger rod design with a two rod system. In the two rod system, one rod goes from the lower to the upper bridge and the other goes from the upper bridge to the roof truss (Moncarz, Fellow, and Taylor 2000). This change in the hanger rod more or less doubled the load to be transferred on the 4th floor box beam-hanger rod connection (Marshall 1982). The design load for the fourth floor walkway was 20.3 kips (90 kN) when under the new design system the connection should have had a design load of double that, 40.7 kips (181 kN) (Texas A&M University 2009). The original hanger rod design would have been able to hold the load at the time of the collapse (Marshall 1982). Within a year, the box beams resting on the supporting rod nuts and washers were deformed, so that the box beam resting on the nuts and washers on the rods could no longer hold up the load, thus the box beams detached from the ceiling rods and the fourth and second floor walkways of the Hotel. Had this change in the hanger rod design not been made, the maximum capacity of the design connection would have been far short of Kansas City building code requirements which require a minimum value of 33.9 kips (151 kN). The value for the original connection would have been approximately 20.5 kips (91 kN) meaning that the original connection capacity would have been only 60% of what was expected by building codes (Texas A&M University 2009). Apart from the design change, poor management and decisions on the part of the construction firm and engineering firm, and the failure of the connection to meet building codes, other factors resulted in the collapse of the hotel. Quality of workmanship, improper welding and connections, inadequate building material, failure on the part of the hotel to hire building inspectors as well as failure of the building inspectors to allow the building to be occupied despite its hazards were also factors in the collapse (Kieckhafer, Moses, and Warta 2010).
Missed Opportunities and Miscommunication
One year into construction on the Hyatt skywalks, G.C.E. Engineers submitted a series of drawings detailing the connections points suspending the walkways to the fabricator, Havens Steel Company. Originally proposing that a single hanger rod should support the walkways, G.C.E. approved of the fabricator’s suggestion to redesign this connection using two smaller rods. However, a miscommunication occurred between the two groups when neither G.C.E. nor the fabricator made calculations on the strength of the beam, each claiming that they themselves were not responsible. A second opportunity to test the connection points presented itself during the construction phase when the atrium ceiling collapsed: calculations were then made at these crucial points, but not on the skywalk connections. G.C.E. was later held responsible for allowing the design to pass inspection although it was far below Kansas City building codes. Had these points been tested, G.C.E. would have discovered that the critical connections points at these box beams supported only one third of the load capacity required (Nelson 2006).
Lessons Learned
As a result of the fatal miscommunication, the American Society of Civil Engineers has now set the precedent that responsibility lies with the engineer's seal. That is, that whoever places their seal of approval upon a set of plans carries the responsibility for the building and the outcome. It is now also required that all load bearing calculations must be checked by a city appointed engineer and that checks be formal and not “spot checks” (Luth 2000). As an industry, it is important for all responsible parties (architects, engineers, fabricators, etc.) to understand the challenge learned as a result of this fatality. Design presents the industry with a challenge to anticipate any failed detail and to correct it within the design process (BBC Horizon 1987).
Impact on the Industry
After the failed skywalk collapse at Hyatt Regency, the industry was forced to fabricate a new design objective. Suspended skywalks would no longer be an option after the 114-person fatality and was therefore no longer a suitable design solution. The Hyatt Regency Hotel, previously one of the greater attractions in the area, was now forced to pay over $140 million to victims and victims’ families in legal claims over the collapse (Roe 2010). Instead, the industry was required to make the walkways actually appear as solid as they would now structurally be. Hyatt now has a single span walkway supported by pillars that are anchored deep into the rock below the hotel. It is also less common now for fabricators to have professional engineers on staff. This has then led to a decrease in fabricators offering professional services (BBC 1987).
Lessons Not Learned
Beyond the tragedy of 114 lives lost and the great number of injuries is the tragedy of how a single error as a result of miscommunication cost the careers of many engineers, including the reputation of Jack Gillum, head of G.C.E.. This disaster could have been avoided by checking the calculations at these critical points. Engineers following the incident were able to develop many structurally sound solutions for the rebuild of the Hyatt walkways, but it is a complete advantage to create a new solution when the crucial error is already known (Luth 2000). What is worse is that this collapse could certainly occur again, because professionals are constantly presented with endless variables that could lead to destruction just as a result of miscalculation. Overlooking these checkpoints is a simple procedural error that does still occur. Sixteen months of gradual deformation upon the box beam joint at the Hyatt skywalk proves that it is only a matter of time until a fatal error is discovered (Nelson 2006). Going beyond the boundaries of the state of Missouri, a similar case can be found as recently as 2006 in Germany. After heavy snowfall, the roof of an ice rink in the town of Bad Reichenhall collapsed. A few years before the fatal collapse, formal complaints were filed concerning the structural integrity of the roof as well as the numerous roof leaks. Rather than investigating these complaints fully, insufficient spot checks were done. Had thorough investigations into these complaints been carried out, the weakness in the structural members from water damage would have been found. The negligence of the architects and engineers that worked on the Hyatt Regency was not learned from in this case where simple checks during and after construction could have completely prevented a collapse (Associated Press 2006).
References
1. Department of Philosophy and Department of Mechanical Engineering
Texas A&M University. (February, 22, 2009). “Engineering Ethics: The Kansas City Hyatt Regency Walkways Collapse.” <**http://ethics.tamu.edu/ethics/hyatt/hyatt1.htm**> (February 10, 2010.) This Presentation Guide provides step-by-step instruction for a debate concerning the building failure. This paper discusses ethical and structural issues surrounding the building failure.
2. Kieckhafer, Alex; Moses, Tony; Warta, Andrew. “Kansas City Hyatt Regency Skywalk Collapse.” <http://em-jaturner.unl.edu/courses/em223/Group1/sld008.htm> (February 10, 2010). A slideshow that contains images depicting the original design and the changed design. Causes of the failure and images depicting the changed supports are also included. Static force diagrams are included, and also possible design improvements.
3. Luth, Gregory P., ASCE, (May.2000) “Chronology and Context of the Hyatt Regency Collapse.” Journal of Performance of Constructed Facilities. This journal article takes a chronological step-by-step look at the events leading up to the walkways collapse. It discusses the causes of the collapse as well as the repercussions that followed.
4. Marshall, Richard D. (1982). “Investigation of the Kansas City Hyatt Regency walkways collapse.” U.S. Dept. of Commerce, National Bureau of Standards. This microfilm investigates the collapse of the Hyatt Walkway. The focus is on the legal aspects surrounding the building failure.
5. Moncarz, Piotr D. P.E., Fellow, ASCE and Taylor, Robert K. P.E. (May. 2000). “Engineering Process Failure-Hyatt Walkway Collapse.” Journal of Performance of Constructed Facilities. 46-50. This journal article explains how the collapse of the Hyatt Walkway occurred and how the engineering community as a whole learned from this building failure.
6. Nelson, Paul (producer). (January 10, 2006). “Seconds from Disaster: Skywalk Collapse.” National Geographic Channel. http://channel.nationalgeographic.com/series/seconds-from-disaster/2570/Overview. (2010). Also posted to YouTube. http://www.youtube.com/watch?v=67WrR_u_erU (June 19, 2008). Documentary: Series video that illustrates the personal experience of victims suffering under the Hyatt Skywalk Collapse. Video and recreated animation cooperate to portray a detailed account of the event. Engineering reports are analyzed to pinpoint the location of the failure in the skywalk structure: two sets of rods replace a single hanger design. The double load upon the beam was flawed from the start.
7. Roe, Jason. “Hotel Horror.” The Kansas City Public Library. <http://www.kclibrary.org/blog/month-kansas-city-history/hotel-horror> (February 10. 2010). Dancers gathered in the atrium to partake in a traditional dance. Two skywalks collapsed killing 114 and injuring many more. Many design flaws are listed, including weight distribution of the second and fourth floor walkways. The engineers responsible for the disaster lost their licenses.
8. (1987). “To Engineer Is Human.” BBC Horizon video posted on YouTube. <http://www.youtube.com/watch?v=7aXr9pXph-w&feature=PlayList&p=2AE89EF989664849&index=1>. (July 4, 2009). Documentary: Video highlights the case and construction prior to the failure. Details are given about the failed connection of the bolt and box beam to the Hyatt skywalk. Coverage is provided regarding the challenges the responsible architects and engineers faced both before and after the collapse, as well as the resulting solutions. July 17, 1981.
Additional References
9. Baura, Gail D. (2006). “Engineering Ethics: An Industrial Perspective.” Elsevier Academic Press Publications, Burlington, Massachusetts. This book includes a chapter solely on the collapse of the Hyatt Walkway through background information. The chapter comments on the design, going step by step through the structure of the building, its collapse and the legal repercussions of the collapse.
10. Associated Press. "German town mourns after ice-rink collapse." MSNBC. <http://www.msnbc.msn.com/id/10596709/>. (January 5, 2006)
Online article: Provides an account of a collapse of a German ice-rink, where the failures were cause by similar negligence and failure to respond to the warning signs of the collapse.
Table of Contents
Kansas City Hyatt Regency Walkway Collapse
Doug Dozier, Sara Holden, Bethany Drab, Matt NeustadterAbstract
On the night of July 17th, 1981, hundreds people were gathered in the Hyatt Regency Hotel to participate in one of the traditional “tea dances.” Many were gathered on the dance floor, and the three various walkways suspended on the floors above. At 7:05pm, the fourth floor walkway collapsed, bringing down the second floor walkway with it. The walkways crashed to the floor, killing 114, and leaving 200 more injured. A flaw in the connection of the walkways and support rods was to blame, and the engineer who signed off on the design lost their licenses. The hotel was restored, and is currently functioning under normal conditions.
Key Words
Box beam, hanger rod, collapse, skywalk, Hyatt Regency, Havens Steel Company, G.C.E. Inc. engineering firm
Events Leading Up to Collapse
On the night of the collapse, the Hyatt Regency Hotel was hosting a tea-dance party in their atrium lobby (Texas A&M University 2009). The total number of people in attendance was estimated to be over 300 (Marshall 1982). Many of these party-goers were standing and dancing on the suspended walkways in the atrium just before the second and fourth floor walkways collapsed to the atrium floor (Texas A&M University 2009). Forty people were located on the second walkway, even though the upper bound for a single spanned occupancy is 16 (Marshall 1982). At 7:05pm, popping was heard up to 30 meters away as the final restraining nut ripped through the box beam (Nelson 2006).
Causes of the Collapse
The Hyatt Regency Hotel walkway collapse did not occur as a result of innovative design, construction or material use, but rather as a product of numerous management errors. It was these fatal management errors that resulted in the flawed construction detail to be used in the support system of the walkways of the Hotel Atrium (Moncarz, Fellow, and Taylor 2000). Various events and disputed communications between G.C.E. engineers and Havens Steel Company resulted in the design change from a single to a double hanger rod box beam connection on the fourth floor walkways (Texas A&M University 2009). The original design detail of continuous threading of the nut through two stories of the building appeared to be impractical to the contractor and as such he changed the design drawings (Shop Drawing 30 and Erection Drawing E-3) and replaced the original single hanger rod design with a two rod system. In the two rod system, one rod goes from the lower to the upper bridge and the other goes from the upper bridge to the roof truss (Moncarz, Fellow, and Taylor 2000). This change in the hanger rod more or less doubled the load to be transferred on the 4th floor box beam-hanger rod connection (Marshall 1982). The design load for the fourth floor walkway was 20.3 kips (90 kN) when under the new design system the connection should have had a design load of double that, 40.7 kips (181 kN) (Texas A&M University 2009). The original hanger rod design would have been able to hold the load at the time of the collapse (Marshall 1982). Within a year, the box beams resting on the supporting rod nuts and washers were deformed, so that the box beam resting on the nuts and washers on the rods could no longer hold up the load, thus the box beams detached from the ceiling rods and the fourth and second floor walkways of the Hotel. Had this change in the hanger rod design not been made, the maximum capacity of the design connection would have been far short of Kansas City building code requirements which require a minimum value of 33.9 kips (151 kN). The value for the original connection would have been approximately 20.5 kips (91 kN) meaning that the original connection capacity would have been only 60% of what was expected by building codes (Texas A&M University 2009). Apart from the design change, poor management and decisions on the part of the construction firm and engineering firm, and the failure of the connection to meet building codes, other factors resulted in the collapse of the hotel. Quality of workmanship, improper welding and connections, inadequate building material, failure on the part of the hotel to hire building inspectors as well as failure of the building inspectors to allow the building to be occupied despite its hazards were also factors in the collapse (Kieckhafer, Moses, and Warta 2010).
Missed Opportunities and Miscommunication
One year into construction on the Hyatt skywalks, G.C.E. Engineers submitted a series of drawings detailing the connections points suspending the walkways to the fabricator, Havens Steel Company. Originally proposing that a single hanger rod should support the walkways, G.C.E. approved of the fabricator’s suggestion to redesign this connection using two smaller rods. However, a miscommunication occurred between the two groups when neither G.C.E. nor the fabricator made calculations on the strength of the beam, each claiming that they themselves were not responsible. A second opportunity to test the connection points presented itself during the construction phase when the atrium ceiling collapsed: calculations were then made at these crucial points, but not on the skywalk connections. G.C.E. was later held responsible for allowing the design to pass inspection although it was far below Kansas City building codes. Had these points been tested, G.C.E. would have discovered that the critical connections points at these box beams supported only one third of the load capacity required (Nelson 2006).
Lessons Learned
As a result of the fatal miscommunication, the American Society of Civil Engineers has now set the precedent that responsibility lies with the engineer's seal. That is, that whoever places their seal of approval upon a set of plans carries the responsibility for the building and the outcome. It is now also required that all load bearing calculations must be checked by a city appointed engineer and that checks be formal and not “spot checks” (Luth 2000). As an industry, it is important for all responsible parties (architects, engineers, fabricators, etc.) to understand the challenge learned as a result of this fatality. Design presents the industry with a challenge to anticipate any failed detail and to correct it within the design process (BBC Horizon 1987).
Impact on the Industry
After the failed skywalk collapse at Hyatt Regency, the industry was forced to fabricate a new design objective. Suspended skywalks would no longer be an option after the 114-person fatality and was therefore no longer a suitable design solution. The Hyatt Regency Hotel, previously one of the greater attractions in the area, was now forced to pay over $140 million to victims and victims’ families in legal claims over the collapse (Roe 2010). Instead, the industry was required to make the walkways actually appear as solid as they would now structurally be. Hyatt now has a single span walkway supported by pillars that are anchored deep into the rock below the hotel. It is also less common now for fabricators to have professional engineers on staff. This has then led to a decrease in fabricators offering professional services (BBC 1987).
Lessons Not Learned
Beyond the tragedy of 114 lives lost and the great number of injuries is the tragedy of how a single error as a result of miscommunication cost the careers of many engineers, including the reputation of Jack Gillum, head of G.C.E.. This disaster could have been avoided by checking the calculations at these critical points. Engineers following the incident were able to develop many structurally sound solutions for the rebuild of the Hyatt walkways, but it is a complete advantage to create a new solution when the crucial error is already known (Luth 2000). What is worse is that this collapse could certainly occur again, because professionals are constantly presented with endless variables that could lead to destruction just as a result of miscalculation. Overlooking these checkpoints is a simple procedural error that does still occur. Sixteen months of gradual deformation upon the box beam joint at the Hyatt skywalk proves that it is only a matter of time until a fatal error is discovered (Nelson 2006). Going beyond the boundaries of the state of Missouri, a similar case can be found as recently as 2006 in Germany. After heavy snowfall, the roof of an ice rink in the town of Bad Reichenhall collapsed. A few years before the fatal collapse, formal complaints were filed concerning the structural integrity of the roof as well as the numerous roof leaks. Rather than investigating these complaints fully, insufficient spot checks were done. Had thorough investigations into these complaints been carried out, the weakness in the structural members from water damage would have been found. The negligence of the architects and engineers that worked on the Hyatt Regency was not learned from in this case where simple checks during and after construction could have completely prevented a collapse (Associated Press 2006).
References
1. Department of Philosophy and Department of Mechanical Engineering
Texas A&M University. (February, 22, 2009). “Engineering Ethics: The Kansas City Hyatt Regency Walkways Collapse.” <**http://ethics.tamu.edu/ethics/hyatt/hyatt1.htm**> (February 10, 2010.)
This Presentation Guide provides step-by-step instruction for a debate concerning the building failure. This paper discusses ethical and structural issues surrounding the building failure.
2. Kieckhafer, Alex; Moses, Tony; Warta, Andrew. “Kansas City Hyatt Regency Skywalk Collapse.” <http://em-jaturner.unl.edu/courses/em223/Group1/sld008.htm> (February 10, 2010).
A slideshow that contains images depicting the original design and the changed design. Causes of the failure and images depicting the changed supports are also included. Static force diagrams are included, and also possible design improvements.
3. Luth, Gregory P., ASCE, (May.2000) “Chronology and Context of the Hyatt Regency Collapse.” Journal of Performance of Constructed Facilities.
This journal article takes a chronological step-by-step look at the events leading up to the walkways collapse. It discusses the causes of the collapse as well as the repercussions that followed.
4. Marshall, Richard D. (1982). “Investigation of the Kansas City Hyatt Regency walkways collapse.” U.S. Dept. of Commerce, National Bureau of Standards.
This microfilm investigates the collapse of the Hyatt Walkway. The focus is on the legal aspects surrounding the building failure.
5. Moncarz, Piotr D. P.E., Fellow, ASCE and Taylor, Robert K. P.E. (May. 2000). “Engineering Process Failure-Hyatt Walkway Collapse.” Journal of Performance of Constructed Facilities. 46-50.
This journal article explains how the collapse of the Hyatt Walkway occurred and how the engineering community as a whole learned from this building failure.
6. Nelson, Paul (producer). (January 10, 2006). “Seconds from Disaster: Skywalk Collapse.” National Geographic Channel. http://channel.nationalgeographic.com/series/seconds-from-disaster/2570/Overview. (2010). Also posted to YouTube. http://www.youtube.com/watch?v=67WrR_u_erU (June 19, 2008).
Documentary: Series video that illustrates the personal experience of victims suffering under the Hyatt Skywalk Collapse. Video and recreated animation cooperate to portray a detailed account of the event. Engineering reports are analyzed to pinpoint the location of the failure in the skywalk structure: two sets of rods replace a single hanger design. The double load upon the beam was flawed from the start.
7. Roe, Jason. “Hotel Horror.” The Kansas City Public Library. <http://www.kclibrary.org/blog/month-kansas-city-history/hotel-horror> (February 10. 2010).
Dancers gathered in the atrium to partake in a traditional dance. Two skywalks collapsed killing 114 and injuring many more. Many design flaws are listed, including weight distribution of the second and fourth floor walkways. The engineers responsible for the disaster lost their licenses.
8. (1987). “To Engineer Is Human.” BBC Horizon video posted on YouTube. <http://www.youtube.com/watch?v=7aXr9pXph-w&feature=PlayList&p=2AE89EF989664849&index=1>. (July 4, 2009).
Documentary: Video highlights the case and construction prior to the failure. Details are given about the failed connection of the bolt and box beam to the Hyatt skywalk. Coverage is provided regarding the challenges the responsible architects and engineers faced both before and after the collapse, as well as the resulting solutions. July 17, 1981.
Additional References
9. Baura, Gail D. (2006). “Engineering Ethics: An Industrial Perspective.” Elsevier Academic Press Publications, Burlington, Massachusetts.
This book includes a chapter solely on the collapse of the Hyatt Walkway through background information. The chapter comments on the design, going step by step through the structure of the building, its collapse and the legal repercussions of the collapse.
10. Associated Press. "German town mourns after ice-rink collapse." MSNBC. <http://www.msnbc.msn.com/id/10596709/>. (January 5, 2006)
Online article: Provides an account of a collapse of a German ice-rink, where the failures were cause by similar negligence and failure to respond to the warning signs of the collapse.