Hyatt regency hotel walkway collapse

case study questions 1-7

BEFORE THE COLLAPSE 0 Friday evening, July 17, 1981, the lobby of the west houl in Kansas City was crowded with dancers and other just enjoying the Ng band sound swinging them into another weekend. Many watched from architecturally graceful walkways suspended across the grand expans of the columless strium, and many tapped their toes and way to the strains of "Satin Doll The petke undulations of the walkways themselves only added to the general celebration of the evening which was to end with the catastrophie collapse of two crowded walkways onto the even more crowded floor below. Thus the Kansas City Hymt Regency Hotel became a synonym for the greatest structural tragedy in the history of the United States, and grieving, accusations, investip tions, and lawsuits would continue for years after the accident There were 114 people killed and almost 200 others injured, and it was estimated that approximately half of Kansas City's population was directly or indirectly touched by the tragedy, Sur vivons everywhere wondered how such a terrible thing could have happened, and the national news media covered the incident tensely for several days. But soon the story was drives of the front page and received in and less notiekopt in the Kansas City newspaper, which of course had a more immediate interest in the story. The newspapers engaged consulting engineers to review the evidence and advise their raden of the causes of the accident, and within four days of the structural failure, the front page of the Ken Cly Star carried in lieu of headlines technical drwinp of design details that pinpointed the cause. Investigative reporting that would win the Pulitzer Prize identified the skywalk weak link and explained how a suspension rod tore through a borbem to initiate the progressive collapse of the weakened structure. A deviation in design in the way the rods connected the lower sky. walk to the upper and the upper to the riling of the atrium was clearly described and broed in on the stimate cause of the scedent Architectural drawings for the original design of the expension system for the hotel's skywalks showed each point of sport A simple long rod attached to the ceiling and pasting throws the crow bearms on which the walkways rested. The two walkways were hung on below the other by washers and bolts under their respective for bear. This original design could work in princi ple in the long rods were strong enough the washers and bolts arge enough and the floor and heavy enough to support of only the walkways there but also the crowds of people that might be expected to emble and perhaps even to run, jump, or dance along them. Preciwly what "wrong enough." "harpe enough." and "heavy cough translate into in terms of numbers representing engineering resses and trains is normally governed by building codes, but such codes apparently do explicitly treat anique rural concept like the Hyatt Regency sky But even if they do not specifically address the design of sky walk, building codes do require a certain level of strength for steel roda in tension and de specify such assumptions w how much weight people can be expected to place upon houl walkways whether or not suspended from a celling or another walkway, by these standards, the original support system planned for the Hyatt Regency walkways was found by investigators at the National Bureau of Standards to be underdesined. The supports would have been only sixty percent strong as they should have been according to the Kansas City Building Code. However, since the writers of building codes want designs to be on the safe side and to provide plenty of marge for error not only in assumptions and calculations but also in making and construction, the codes require much more than minimum strength. Thus the walkways as originally designed, though songs they should have heen, would probably not have fallen and their nonconformity with the code might never have been discovered Unfortunately, someone looking at the original details of the connection must have said he had a better idea of ancier way to hang one skywalk beneath the other and bach from the sixty foot-high ceiling of the atrium. for the connection on the original architectural drawing was difficult, if not impossible to install The original concept of a single rod extending from each coiling connection, passing through holes is a beam supporting the fourth floor wall way about the feet bdew and continuing for another thirty feet before passing through the beam of the cond Hoor walkway would indeed have been an unwieldy construction task and someone's sugestion that the short rods wewed in place of each long one must have had an immediate appeal to anyone involved with the erection of the walkways (We alle member or can imagine how easily bent the longest places of our Erector sets were and how they never looked quite the same sur we tried to righten them out again In the modified connection system, one support rod extended from the ceiling through holes in the top walkway's beam, which rested on a Washer and mul threaded on the end of the rod. Through another set of holes a few inches toward the inside of the upper walkway, a cond rod was hung down, provenied from being pulled through by another washer and nut, and lower walkway beam was supported from this rod in the same way the upper one was from the upper rod. This was certainly are way of enembling the skywalks, for it is a much more familias to thread rods at their ends and fasten nuts to them that to thread a forty-ve-foot long rod along its entire length or to cut threads only where the rods were to pass through the upper walkway's beam, as suggested by the original drawings. But no matter how much more convenient to set the new rod configuration effectively doubled the push of the water on the box bean sp porting the upper walkway's foor, and this made the already underdesigned skywalks barely able to support their own weight We can appreciate the mechanics of the problem by considering a simple analogs, replacing the original rod with a rope and the two always with twe people hanging out the rope. Each per son's weight is transferred to the rope through the hands gripping k. The support of the walkways in the original design is analogous to the two people hanging persely, one below the other to the same rope. If the rope were strong enough and the individuals prips were tight enough each person could hold on the rope without falling however, the lower rope henger groot the me rope but another tied to the lap of the punon show, the 441 The A HYATT REGENCY WALKWAY COLLAPSE INTRODUCTION upper person is bodies, erroghly twice own weight hofthe rope that heel but the ength of the top pence's pip of his grip wasily abke to support his ich het is just rely wrong enough oppor the doubled with hande wond to give it and the poll. Evestually, even the slightest ling of the lower penon could own the upper rip and send them both crushing to the ground In the wake of the tragedy the National Hures of Sun dards only determined that the original design was should hawwe, but she found by the beam android connect the detail that effectively and the that the skywalks as construed were barely able top port their own weight, the confirming that the wywalls were sident just waiting to happen There were apparently weal incidents during construction of the Hyatt Regency Hold when the weakne of the walkways could have been deved, but warnings of wiede, these signal of potential der were not heeded. The lobby four collaped when the hotel was under construction, and checks of many rural details including those of the skywalks we ordered but. Apparently there and how bean connections were either not checked or not found wanting Aher the walkways were up there were reports that sitios worken found the nevated shorts over the transedy under heavy who barrons, but the construction that was simply rerouted and the desem were apparently will not checked or found wanting Though it to may sin retrospect the weak in the Hyatt Regewyder sind walkway how podtienis the myriad other details of the unique Construction However, her the widest there were Monday mornine hacks alors, and they were nowhere so much in evidence in the letter to the editor action of Expert New Record. The original details of the whitectural drawings did show athy how the single long rod was the manufactured, and in the wake of the accident made clear that at last one another widely circulated weekly of the contraction industry though the original architectural drawing called for personas those that would be needed for one of M. C Escher's buildings Indeed, what was published the original drawing showed a mut areas hees fost up the single rod and many maden Appet rached their heads to how that it would then he rutched their heads to how that ut would get there. They pointed out that the whol length of rod between the aut ad the and would have the threaded, which the drawings sorshow of the threaded section of the rod would have to her than the rol. Onder summed up the con Adathap change can be completely without blame when the change is made Within a month of the letters pondering the "Hyni of putting. Men for wp arodvoley of the Appeared in Eng News Record the being headline" Hyatt Puuk Solution. The readers did not take the archite tural drawing literally and pointed out how a pele de ince veniently long rods de contemd by a lewe one that affections a coupling device to diminate the need for the two od rating the da per condition that rewed. Another radera pouble way in which the same med chaud section that sited the band have been welded diferico rutiewe provide a wronger wareg word one case wonder how many other published in the mall of Een New Red When I need the Hyake Ny faller in an artikel Ter Review the editor of that magazine Alerceived an ually large amount of mail on the Sleeve pik die host of other de tonto the word by deshe Apparel not red Ephery News Renow and who diners that such a caudomach rok Ariun Cering Web Arnfloor maahan ban Bored to end The letters to the editor and many editorials and articles in the pages of profesional engineering publications inspired by the Hyatt Regency social ested that it would not have hap pened were experienced deipers and detailers involved. They would most likely have used a tried-and-true detail that they knew would work, or they would likely have looked very carefully at such an unusual one specified for the walkway support. This Kind of claim can never be verified, of course, but it is no doubt more likely for someone with a considerable amount of experience to be able to spot things that will not work. However, just as ne one who knows of the Tacoma Narrow Bridge is likely to ignore the effect of wind on suspension bridge. So noon who remem bers the Hyatt Regency skywalks is likely to let another rod-beam connection cape con rutiny. Thus the tragedy nodok made lot of inexperienced detailers soddenly much more experienced And it is precisely to keep these lentons in the minds of young engines that failures should be past part of the engineer ing literature After Twenty months of investigation, the US attomey and the Jackson County, Missouri, prosecutor announced jointly that they had found no evidence that either a federal or a state crime was committed in connection with the Hyatt Regency skywalks col. lapse. However, within two months of the annoncenent, the attorney general of Minouri filed a complaint agaimt the engi neers responsible for the design of the hotel. They were charged with grom negligence" in the design and analysis of the su pended walkways. Specifically, they were charged with failure to perform calculations to determine the load capacity of the bridge rods and connections"failure to check if the roda specified would be adequate after the desip change were made, and failure to perform an analysis of the walkway suspension system as re- quested by the owner a section of the hotel roof collapsed dering construction. The law is no more an exact wice than engineering, and the strength or weaknew of the attorney gmer's Calle avaits the rest of a trial as this is being written Once one of the hanger roda pulled through the box bem connection under the Hyatt Regency walkway, that rod clearly could no longer carry is share of the weight of the skywalks and the people on them. However, had the structure of bees to marginally designed the other rods might have redistributed the unsupported weight among them, and the walkway night only have sugged it at the broken connection. This would have skened the hotel management to the problem and had this wars ing been taken more riously than the signs of the walkway's fimines during construction, tedy might never have o curred. Thus designen often try to build into the structures what are known as almele low to accommodate the routed traffic of stress and train when any one land path becomes un Wilable for whatever When alemate load paths can take the extra teor de not even catastrophic failures can occur. The Hyatt Regency skywalks were a kind of buipemross the herd's run, and bridges are oftendering structures because of the several functions they serve. In the case of the skywalks, there was architectural effect of openness to mained in the airim oby. which had come to be trademark of Hymit holds. When the wywalks collapwed there was immediate concern about the safety of other daring lobby design, but now quite them as the Kama City concept, Chicago ely inspection ordered the re- ricted of suspended areas of the city Hyatt Regency until reinforcements could be made, bu generally the effects of the Kansas City are will be new construction that might be some resemblance to I led walks Poor www.com THE KANSAS CITY STAR. vitical design change linked to collapse Hyatt's sky walks Within days of the skywalk tragedy a third, remaining elevated walkway that had been suspended alongside the two that col- lapsed was dismantled and removed from the lobby in the middle of the night despite protests from the mayor of Kansas City. The owners of the hotel argued that the remaining walkway presented a hazard to workers and others in the building, but attorneys for some of the victims objected, claiming that evidence would be destroyed, and engineers interested in studying the cause of the accident lamented the removal of the only extant structure any. where near equivalent to that which had collapsed. Had the third walkway not been removed so precipitately, its behavior under the feet of dancers might or might not have confirmed the theory that the walkways responded to the tempo of the dance the way a wine glass can to a soprano's high note. Today the Hyatt Regency lobby in Kansas City is spanned by a single walkway resting on stout columns sitting on the solid floor. While the open expanse of the lobby is perhaps diminished architecturally, the new design is no doubt intended to provide a sense of security and bear little resemblance to the fragile sky. walks. But even though the reconstructed walkway in the hotel lobby may be as safe as one can imagine, the apparent absence of a skyhook-like suspension system in other bridges has not meant that they were not in fact lacking alternate load paths to compen. sate for potential failures of the primary structural supports. The Hipett Regency Present Day Renamed "Sheraton Kansas City Hotel at Crown Center" SKYWALK MEMORIAL Carolyte Hyde gewy Karty the deedest budding in American story De Two floors directly be one out for und of the woning, cranes and berdew well wird utryd ed underton The collapse of two suspended walkways in the Kansas City Hyatt Regency Hotel ta 1981 killed over one hundred people and was the worst sceident due to a structural failure in the history of the United States. There were many theories offered for the cause of the collapse, including the presence of too many people dancing on the walkways, recalling the collapse of early suspension bridges under the foot of marching soldiers. The real cause of the failure was quickly traced to a single change in the design of a support detail, apparently made to facilitate the erection of the skywalks. The Kansas City Sun which had hired an engineer as a consultant on the story, revealed the true cause within days of the accident in this Pulitze Prize winning story. Later tests at the National Bureau of Standards confirmed the causo be in the detail Lessons can be drawn from this Tragedy 1) Connection should be designed by a qualified engineer at some point in the design and construction process 2) An internal quality review should be thorough-more than sper checking and should include a formal check of details on the structural drawings *) Cuestions posed during design and construction should not be dedu should be given the stront attention on a project with an ceted schedule 4) When there are changes in personne, Mops should be taken that are a wooth transition and folltransfer of knowledge about the design the lading up to the personnel change 5) Even small seemingly insignificant changes in concept should be handled through a process that compuls the participants to focus on potential issues, Engineerinsity building department sted rot be depended upon for fi In the design intent roles should catch any errors before documents for construction 1. Breifly describe the cause of this falure. 2. What is the Simple Analogy that expains the weight transfer from the original to the as built connection detail? The Des 3. Why was it necessary to change the original connection system? 4. From the image shown, explain how the imposed load P on the skywalk doubled to a load 2P when the original detail was modified 5. How did the broken sprinkler system compound the resue efforts? 6. What legal charges did the Attorney General of Missoun file against the engineers responsible for the design and construction of the hotel? 7. On page 8, I have listed 6 Lessons learned from this structural failure. Which of these 6 lessons do you feel is most important to you? Why? BEFORE THE COLLAPSE 0 Friday evening, July 17, 1981, the lobby of the west houl in Kansas City was crowded with dancers and other just enjoying the Ng band sound swinging them into another weekend. Many watched from architecturally graceful walkways suspended across the grand expans of the columless strium, and many tapped their toes and way to the strains of "Satin Doll The petke undulations of the walkways themselves only added to the general celebration of the evening which was to end with the catastrophie collapse of two crowded walkways onto the even more crowded floor below. Thus the Kansas City Hymt Regency Hotel became a synonym for the greatest structural tragedy in the history of the United States, and grieving, accusations, investip tions, and lawsuits would continue for years after the accident There were 114 people killed and almost 200 others injured, and it was estimated that approximately half of Kansas City's population was directly or indirectly touched by the tragedy, Sur vivons everywhere wondered how such a terrible thing could have happened, and the national news media covered the incident tensely for several days. But soon the story was drives of the front page and received in and less notiekopt in the Kansas City newspaper, which of course had a more immediate interest in the story. The newspapers engaged consulting engineers to review the evidence and advise their raden of the causes of the accident, and within four days of the structural failure, the front page of the Ken Cly Star carried in lieu of headlines technical drwinp of design details that pinpointed the cause. Investigative reporting that would win the Pulitzer Prize identified the skywalk weak link and explained how a suspension rod tore through a borbem to initiate the progressive collapse of the weakened structure. A deviation in design in the way the rods connected the lower sky. walk to the upper and the upper to the riling of the atrium was clearly described and broed in on the stimate cause of the scedent Architectural drawings for the original design of the expension system for the hotel's skywalks showed each point of sport A simple long rod attached to the ceiling and pasting throws the crow bearms on which the walkways rested. The two walkways were hung on below the other by washers and bolts under their respective for bear. This original design could work in princi ple in the long rods were strong enough the washers and bolts arge enough and the floor and heavy enough to support of only the walkways there but also the crowds of people that might be expected to emble and perhaps even to run, jump, or dance along them. Preciwly what "wrong enough." "harpe enough." and "heavy cough translate into in terms of numbers representing engineering resses and trains is normally governed by building codes, but such codes apparently do explicitly treat anique rural concept like the Hyatt Regency sky But even if they do not specifically address the design of sky walk, building codes do require a certain level of strength for steel roda in tension and de specify such assumptions w how much weight people can be expected to place upon houl walkways whether or not suspended from a celling or another walkway, by these standards, the original support system planned for the Hyatt Regency walkways was found by investigators at the National Bureau of Standards to be underdesined. The supports would have been only sixty percent strong as they should have been according to the Kansas City Building Code. However, since the writers of building codes want designs to be on the safe side and to provide plenty of marge for error not only in assumptions and calculations but also in making and construction, the codes require much more than minimum strength. Thus the walkways as originally designed, though songs they should have heen, would probably not have fallen and their nonconformity with the code might never have been discovered Unfortunately, someone looking at the original details of the connection must have said he had a better idea of ancier way to hang one skywalk beneath the other and bach from the sixty foot-high ceiling of the atrium. for the connection on the original architectural drawing was difficult, if not impossible to install The original concept of a single rod extending from each coiling connection, passing through holes is a beam supporting the fourth floor wall way about the feet bdew and continuing for another thirty feet before passing through the beam of the cond Hoor walkway would indeed have been an unwieldy construction task and someone's sugestion that the short rods wewed in place of each long one must have had an immediate appeal to anyone involved with the erection of the walkways (We alle member or can imagine how easily bent the longest places of our Erector sets were and how they never looked quite the same sur we tried to righten them out again In the modified connection system, one support rod extended from the ceiling through holes in the top walkway's beam, which rested on a Washer and mul threaded on the end of the rod. Through another set of holes a few inches toward the inside of the upper walkway, a cond rod was hung down, provenied from being pulled through by another washer and nut, and lower walkway beam was supported from this rod in the same way the upper one was from the upper rod. This was certainly are way of enembling the skywalks, for it is a much more familias to thread rods at their ends and fasten nuts to them that to thread a forty-ve-foot long rod along its entire length or to cut threads only where the rods were to pass through the upper walkway's beam, as suggested by the original drawings. But no matter how much more convenient to set the new rod configuration effectively doubled the push of the water on the box bean sp porting the upper walkway's foor, and this made the already underdesigned skywalks barely able to support their own weight We can appreciate the mechanics of the problem by considering a simple analogs, replacing the original rod with a rope and the two always with twe people hanging out the rope. Each per son's weight is transferred to the rope through the hands gripping k. The support of the walkways in the original design is analogous to the two people hanging persely, one below the other to the same rope. If the rope were strong enough and the individuals prips were tight enough each person could hold on the rope without falling however, the lower rope henger groot the me rope but another tied to the lap of the punon show, the 441 The A HYATT REGENCY WALKWAY COLLAPSE INTRODUCTION upper person is bodies, erroghly twice own weight hofthe rope that heel but the ength of the top pence's pip of his grip wasily abke to support his ich het is just rely wrong enough oppor the doubled with hande wond to give it and the poll. Evestually, even the slightest ling of the lower penon could own the upper rip and send them both crushing to the ground In the wake of the tragedy the National Hures of Sun dards only determined that the original design was should hawwe, but she found by the beam android connect the detail that effectively and the that the skywalks as construed were barely able top port their own weight, the confirming that the wywalls were sident just waiting to happen There were apparently weal incidents during construction of the Hyatt Regency Hold when the weakne of the walkways could have been deved, but warnings of wiede, these signal of potential der were not heeded. The lobby four collaped when the hotel was under construction, and checks of many rural details including those of the skywalks we ordered but. Apparently there and how bean connections were either not checked or not found wanting Aher the walkways were up there were reports that sitios worken found the nevated shorts over the transedy under heavy who barrons, but the construction that was simply rerouted and the desem were apparently will not checked or found wanting Though it to may sin retrospect the weak in the Hyatt Regewyder sind walkway how podtienis the myriad other details of the unique Construction However, her the widest there were Monday mornine hacks alors, and they were nowhere so much in evidence in the letter to the editor action of Expert New Record. The original details of the whitectural drawings did show athy how the single long rod was the manufactured, and in the wake of the accident made clear that at last one another widely circulated weekly of the contraction industry though the original architectural drawing called for personas those that would be needed for one of M. C Escher's buildings Indeed, what was published the original drawing showed a mut areas hees fost up the single rod and many maden Appet rached their heads to how that it would then he rutched their heads to how that ut would get there. They pointed out that the whol length of rod between the aut ad the and would have the threaded, which the drawings sorshow of the threaded section of the rod would have to her than the rol. Onder summed up the con Adathap change can be completely without blame when the change is made Within a month of the letters pondering the "Hyni of putting. Men for wp arodvoley of the Appeared in Eng News Record the being headline" Hyatt Puuk Solution. The readers did not take the archite tural drawing literally and pointed out how a pele de ince veniently long rods de contemd by a lewe one that affections a coupling device to diminate the need for the two od rating the da per condition that rewed. Another radera pouble way in which the same med chaud section that sited the band have been welded diferico rutiewe provide a wronger wareg word one case wonder how many other published in the mall of Een New Red When I need the Hyake Ny faller in an artikel Ter Review the editor of that magazine Alerceived an ually large amount of mail on the Sleeve pik die host of other de tonto the word by deshe Apparel not red Ephery News Renow and who diners that such a caudomach rok Ariun Cering Web Arnfloor maahan ban Bored to end The letters to the editor and many editorials and articles in the pages of profesional engineering publications inspired by the Hyatt Regency social ested that it would not have hap pened were experienced deipers and detailers involved. They would most likely have used a tried-and-true detail that they knew would work, or they would likely have looked very carefully at such an unusual one specified for the walkway support. This Kind of claim can never be verified, of course, but it is no doubt more likely for someone with a considerable amount of experience to be able to spot things that will not work. However, just as ne one who knows of the Tacoma Narrow Bridge is likely to ignore the effect of wind on suspension bridge. So noon who remem bers the Hyatt Regency skywalks is likely to let another rod-beam connection cape con rutiny. Thus the tragedy nodok made lot of inexperienced detailers soddenly much more experienced And it is precisely to keep these lentons in the minds of young engines that failures should be past part of the engineer ing literature After Twenty months of investigation, the US attomey and the Jackson County, Missouri, prosecutor announced jointly that they had found no evidence that either a federal or a state crime was committed in connection with the Hyatt Regency skywalks col. lapse. However, within two months of the annoncenent, the attorney general of Minouri filed a complaint agaimt the engi neers responsible for the design of the hotel. They were charged with grom negligence" in the design and analysis of the su pended walkways. Specifically, they were charged with failure to perform calculations to determine the load capacity of the bridge rods and connections"failure to check if the roda specified would be adequate after the desip change were made, and failure to perform an analysis of the walkway suspension system as re- quested by the owner a section of the hotel roof collapsed dering construction. The law is no more an exact wice than engineering, and the strength or weaknew of the attorney gmer's Calle avaits the rest of a trial as this is being written Once one of the hanger roda pulled through the box bem connection under the Hyatt Regency walkway, that rod clearly could no longer carry is share of the weight of the skywalks and the people on them. However, had the structure of bees to marginally designed the other rods might have redistributed the unsupported weight among them, and the walkway night only have sugged it at the broken connection. This would have skened the hotel management to the problem and had this wars ing been taken more riously than the signs of the walkway's fimines during construction, tedy might never have o curred. Thus designen often try to build into the structures what are known as almele low to accommodate the routed traffic of stress and train when any one land path becomes un Wilable for whatever When alemate load paths can take the extra teor de not even catastrophic failures can occur. The Hyatt Regency skywalks were a kind of buipemross the herd's run, and bridges are oftendering structures because of the several functions they serve. In the case of the skywalks, there was architectural effect of openness to mained in the airim oby. which had come to be trademark of Hymit holds. When the wywalks collapwed there was immediate concern about the safety of other daring lobby design, but now quite them as the Kama City concept, Chicago ely inspection ordered the re- ricted of suspended areas of the city Hyatt Regency until reinforcements could be made, bu generally the effects of the Kansas City are will be new construction that might be some resemblance to I led walks Poor www.com THE KANSAS CITY STAR. vitical design change linked to collapse Hyatt's sky walks Within days of the skywalk tragedy a third, remaining elevated walkway that had been suspended alongside the two that col- lapsed was dismantled and removed from the lobby in the middle of the night despite protests from the mayor of Kansas City. The owners of the hotel argued that the remaining walkway presented a hazard to workers and others in the building, but attorneys for some of the victims objected, claiming that evidence would be destroyed, and engineers interested in studying the cause of the accident lamented the removal of the only extant structure any. where near equivalent to that which had collapsed. Had the third walkway not been removed so precipitately, its behavior under the feet of dancers might or might not have confirmed the theory that the walkways responded to the tempo of the dance the way a wine glass can to a soprano's high note. Today the Hyatt Regency lobby in Kansas City is spanned by a single walkway resting on stout columns sitting on the solid floor. While the open expanse of the lobby is perhaps diminished architecturally, the new design is no doubt intended to provide a sense of security and bear little resemblance to the fragile sky. walks. But even though the reconstructed walkway in the hotel lobby may be as safe as one can imagine, the apparent absence of a skyhook-like suspension system in other bridges has not meant that they were not in fact lacking alternate load paths to compen. sate for potential failures of the primary structural supports. The Hipett Regency Present Day Renamed "Sheraton Kansas City Hotel at Crown Center" SKYWALK MEMORIAL Carolyte Hyde gewy Karty the deedest budding in American story De Two floors directly be one out for und of the woning, cranes and berdew well wird utryd ed underton The collapse of two suspended walkways in the Kansas City Hyatt Regency Hotel ta 1981 killed over one hundred people and was the worst sceident due to a structural failure in the history of the United States. There were many theories offered for the cause of the collapse, including the presence of too many people dancing on the walkways, recalling the collapse of early suspension bridges under the foot of marching soldiers. The real cause of the failure was quickly traced to a single change in the design of a support detail, apparently made to facilitate the erection of the skywalks. The Kansas City Sun which had hired an engineer as a consultant on the story, revealed the true cause within days of the accident in this Pulitze Prize winning story. Later tests at the National Bureau of Standards confirmed the causo be in the detail Lessons can be drawn from this Tragedy 1) Connection should be designed by a qualified engineer at some point in the design and construction process 2) An internal quality review should be thorough-more than sper checking and should include a formal check of details on the structural drawings *) Cuestions posed during design and construction should not be dedu should be given the stront attention on a project with an ceted schedule 4) When there are changes in personne, Mops should be taken that are a wooth transition and folltransfer of knowledge about the design the lading up to the personnel change 5) Even small seemingly insignificant changes in concept should be handled through a process that compuls the participants to focus on potential issues, Engineerinsity building department sted rot be depended upon for fi In the design intent roles should catch any errors before documents for construction 1. Breifly describe the cause of this falure. 2. What is the Simple Analogy that expains the weight transfer from the original to the as built connection detail? The Des 3. Why was it necessary to change the original connection system? 4. From the image shown, explain how the imposed load P on the skywalk doubled to a load 2P when the original detail was modified 5. How did the broken sprinkler system compound the resue efforts? 6. What legal charges did the Attorney General of Missoun file against the engineers responsible for the design and construction of the hotel? 7. On page 8, I have listed 6 Lessons learned from this structural failure. Which of these 6 lessons do you feel is most important to you? Why