Hyatt Regency walkway collapse


On July 17, 1981, two walkways collapsed at the Hyatt Regency Kansas City hotel in Kansas City, Missouri, one directly above the other. They crashed onto a tea dance being held in the hotel's lobby, killing 114 and injuring 216. As a product of a corporate culture of profound neglect, the disaster contributed many lessons to the study of engineering ethics and errors, and to emergency management. The event remains the deadliest non‑deliberate structural failure in American history, and it was the deadliest structural collapse in the U.S. until the collapse of the World Trade Center towers 20 years later.

Background

The Kansas City Star described a national climate of "high unemployment, inflation and double-digit interest rates pressure on builders to win contracts and complete projects swiftly". Described by the newspaper as fast-tracked, the Hyatt's construction began in May 1978 on the 40-story Hyatt Regency Kansas City. There were numerous delays and setbacks, including the collapse of of the roof. The newspaper observed that "Notable structures around the country were failing at an alarming rate" such as the 1979 Kemper Arena roof collapse and the 1978 Hartford Civic Center roof collapse. The hotel officially opened on July 1, 1980.
Its lobby was one of its defining features, which incorporated a multi-story atrium spanned by elevated walkways suspended from the ceiling. These steel, glass, and concrete crossings connected the second, third, and fourth floors between the north and south wings. The walkways were approximately long and weighed approximately. The fourth-level walkway was directly above the second-level walkway.

Collapse

Approximately 1,600 people gathered in the atrium for a tea dance on the evening of July 17, 1981. The second-level walkway held approximately 40 people at approximately 7:05 p.m., with more on the third and an additional 16 to 20 on the fourth. The fourth-floor bridge was suspended directly over the second-floor bridge, with the third-floor walkway offset several yards from the others. Guests heard popping noises moments before the fourth-floor walkway dropped several inches, paused, then fell completely onto the second-floor walkway. Both walkways then fell to the lobby floor.
The rescue operation lasted 14 hours, directed by Kansas City emergency medical director Joseph Waeckerle. Survivors were buried beneath steel, concrete, and glass which the fire department's jacks could not move. Volunteers responded to an appeal and brought jacks, torches, compressors, jackhammers, concrete saws, and generators from construction companies and suppliers. They also brought cranes and forced the booms through the lobby windows to lift debris. Deputy Fire Chief Arnett Williams recalled this immediate outpouring from the industrial community: "They said 'take what you want'. I don't know if all those people got their equipment back. But no one has ever asked for an accounting and no one has ever submitted a bill."
The dead were taken to a ground floor exhibition area as a makeshift morgue, and the hotel's driveway and front lawn were used as a triage area. Those who could walk were instructed to leave the hotel to simplify the rescue effort, and morphine was given to those who were mortally injured. Rescuers often had to dismember bodies to reach survivors among the wreckage. A surgeon had to amputate one victim's crushed leg with a chainsaw. Blood centers quickly received lineups of hundreds of donors.
Water flooded the lobby from the hotel's ruptured sprinkler system and put trapped survivors at risk of drowning. The final rescued victim, Mark Williams, spent more than nine hours pinned underneath the lower skywalk with both legs dislocated and having nearly drowned before the water was shut off. Visibility was poor because of dust and because the power had been cut to prevent fires. A total of 29 people were rescued from the rubble.

Investigation

The Kansas City Star hired architectural engineer Wayne G. Lischka to investigate the collapse, and he discovered a significant change to the original design of the walkways. Within days, a laboratory at Lehigh University began testing box beams on behalf of the steel fabrication source. The Missouri licensing board, the state Attorney General, and Jackson County would investigate the collapse over the following years. An investigator for the National Bureau of Standards characterized the neglectful corporate culture surrounding the entire Hyatt construction project as "everyone wanting to walk away from responsibility". The NBS's final report cited structural overload resulting from design flaws where "The walkways had only minimal capacity to resist their own weight".
Investigators found that the collapse was the result of changes to the design of the walkway's steel hanger rods. The two walkways were suspended from a set of steel hanger rods, with the second-floor walkway hanging directly under the fourth-floor walkway. The fourth-floor walkway platform was supported on three cross-beams suspended by the steel rods retained by nuts. The cross-beams were box girders made from C-channel strips welded together lengthwise, with a hollow space between them. The original design by Jack D. Gillum and Associates specified three pairs of rods running from the second-floor walkway to the ceiling, passing through the beams of the fourth-floor walkway, with a nut at the middle of each tie rod tightened up to the bottom of the fourth-floor walkway, and a nut at the bottom of each tie rod tightened up to the bottom of the second-floor walkway. Even this original design supported only 60% of the minimum load required by Kansas City building codes.
Havens Steel Company had manufactured the rods, and they objected that the whole rod below the fourth floor would have to be threaded in order to screw on the nuts to hold the fourth-floor walkway in place. These threads would be subject to damage as the fourth-floor structure was hoisted into place. Havens Steel, therefore, proposed that two separate and offset sets of rods be used: the first set suspending the fourth-floor walkway from the ceiling, and the second set suspending the second-floor walkway from the fourth-floor walkway.
This design change would prove to be fatal. In the original design, the beams of the fourth-floor walkway had to support only the weight of the fourth-floor walkway, with the weight of the second-floor walkway supported completely by the rods. In the revised design, however, the fourth-floor beams supported both the fourth and second-floor walkways, but were only strong enough for 30% of that load.
The serious flaws of the revised design were compounded by the fact that both designs placed the bolts directly through a welded joint connecting two C-channels, the weakest structural point in the box beams. The original design was for the welds to be on the sides of the box beams, rather than on the top and bottom. Photographs of the wreckage show excessive deformations of the cross-section. During the failure, the box beams split along the weld and the nut supporting them slipped through the resulting gap, which was consistent with reports that the upper walkway at first fell several inches, after which the nut was held only by the upper side of the box beams; then the upper side of the box beams failed as well, allowing the entire walkway to fall. A court order was required to retrieve the skywalk pieces from storage for examination.
Investigators concluded that the underlying problem was a lack of proper communication between Jack D. Gillum and Associates and Havens Steel. In particular, the drawings prepared by Gillum and Associates were only preliminary sketches, but Havens Steel interpreted them as finalized drawings. Gillum and Associates failed to review the initial design thoroughly and engineer Daniel M. Duncan accepted Havens Steel's proposed plan via a phone call without performing necessary calculations or viewing sketches that would have revealed its serious intrinsic flaws — in particular, doubling the load on the fourth-floor beams. Reports and court testimony cited a feedback loop of architects' unverified assumptions, each having believed that someone else had performed calculations and checked reinforcements but without any actual root in documentation or review channels; onsite workers had neglected to report noticing beams bending.
Jack D. Gillum himself would later reflect that the design flaw was so obvious that "Any first-year engineering student could figure it out", if only it had been checked.

Aftermath

The New York Times said the victims were soon overshadowed by the community's daily preoccupation with the disaster and its polarized attitude of blame-seeking and "vendetta" which soon targeted even the local newspapers, judges, and lawyers: "Seldom has a city's establishment been so emotionally torn by catastrophe as Kansas City's was". The owner of the Kansas City Star Company guessed that the huge victim count ensured that "virtually half the town was affected directly or indirectly by the horror of the tragedy". The newspaper created 16 months worth of Pulitzer Prize-winning investigative coverage of the disaster, putting it at odds with the Kansas City community in general, including the management of Hallmark Cards.
The Missouri Board of Architects, Professional Engineers, and Land Surveyors found the engineers at Jack D. Gillum and Associates who had approved the final drawings to be culpable of gross negligence, misconduct, and unprofessional conduct in the practice of engineering. They were acquitted of all the crimes with which they were initially charged, but the company lost its engineering licenses in the states of Missouri, Kansas, and Texas, as well as its membership with the American Society of Civil Engineers.
In months following the disaster, more than 300 civil lawsuits sought a cumulative total of $3 billion. Of this, at least $140 million was actually awarded to victims and their families across the years. A class action suit seeking punitive damages was won against Crown Center Corporation, which was the hotel's manager and a subsidiary of Hallmark Cards but which did not own the building. That lawsuit yielded $10 million, including $6.5 million dedicated as donations to charitable and civic endeavors which Hallmark called a "healing gesture to help Kansas City put the tragedy of the skywalks' collapse behind it". Each of the approximately 1,600 hotel occupants from that night was unconditionally offered each, of which 1,300 accepted. Every defendant including Hallmark Cards, Crown Center Corporation, the hotel's architects, engineers, and contractor, denied all legal liability including that of the egregious engineering faults.
Several rescuers suffered considerable stress due to their experience and later relied upon each other in an informal support group. Jackhammer operator "Country" Bill Allman died by suicide.
In 1983, local authorities reported that the $5 million hotel reconstruction made the building "possibly the safest in the country". The hotel was renamed the Hyatt Regency Crown Center in 1987, and again the Sheraton Kansas City at Crown Center in 2011. It has been renovated numerous times since, though the lobby retains the same layout and design.

Legacy

The Hyatt Regency collapse remains the deadliest non‑deliberate structural failure in American history, and was the deadliest structural collapse in the U.S. until the collapse of the World Trade Center towers 20 years later. The world responded to this event by upgrading the culture and academic curriculum of engineering ethics and emergency management. In this, the event shares the legacies of the 1984 Bhopal disaster, the 1986 Space Shuttle Challenger disaster, and the 1986 Chernobyl disaster.
This disaster is a case study teaching first responders the "all-hazards approach" to multiple disciplines across jurisdictions, and teaching university engineering ethics classes how the smallest personal responsibility can impact the biggest projects with the worst possible results.
Trade groups such as the American Society of Civil Engineers issued investigations, improved standards of peer reviews, sponsored seminars, and created trade manuals for the improvement of professional standards and public confidence. The Kansas City Codes Administration became its own department, doubling its staff and dedicating a single engineer comprehensively to all aspects of each reviewed building. Kansas City politics and government were reportedly colored for years with investigations against corruption. The Kansas City Star and its associated publication the Kansas City Times won a Pulitzer Prize in 1982 for their 16 months of investigative coverage of the collapse. In 1983, the disaster was cited in the argument against the Reagan Administration's attempt to eliminate an agency of the National Bureau of Standards.
A memorial was dedicated by Skywalk Memorial Foundation, a non-profit organization established for victims of the Hyatt collapse, on November 12, 2015 in Hospital Hill Park across the street from the hotel. This included a $25,000 donation from Hallmark Cards.
Jack D. Gillum was the owner of the engineering company and an engineer of record for the Hyatt project, and he occasionally lectured at engineering conferences for years. Claiming full responsibility and disturbed by his memories "365 days a year", he said he wanted "to scare the daylights out of them" in the hope of preventing future mistakes.