Locations of the second and fourth story walkways which collapsed into the lobby of the Hyatt Regency hotel.
|Time||19:05 (CST) (UTC-6)|
|Date||17 July 1981|
|Location||Kansas City, Missouri, United States|
|Cause||Insufficient Load Capacity|
The Hyatt Regency hotel walkway collapse occurred at the Hyatt Regency Kansas City in Kansas City, Missouri, United States on Friday, July 17, 1981. Two vertically contiguous walkways collapsed onto a dance competition being held in the hotel's lobby. The falling walkways killed 114 and injured a further 216 people. At the time, it was the deadliest structural collapse in U.S. history, not surpassed until the collapse of the south tower of the World Trade Center in 2001.
The construction of the 40-story Hyatt Regency Kansas City began in May 1978. Despite delays and setbacks, including an incident on October 14, 1979 when 2,700 square feet (250 m2) of the atrium roof collapsed due to the failure of one of the connections at its northern end, the hotel officially opened on July 1, 1980.
One of the defining features of the hotel was its lobby, which incorporated a multistory 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 120 ft (37 m) long and weighed approximately 64,000 lb (29,000 kg). The fourth level walkway aligned directly above the second level walkway.
On the evening of July 17, 1981, approximately 1,600 people gathered in the atrium to participate in and watch a dance competition. Many people stood on the two connected walkways. At 7:05 p.m. the second-level walkway held approximately 40 people with more on the third and an additional 16 to 20 on the fourth level who watched the activities of the crowd in the lobby below. The fourth floor bridge was suspended directly over the second floor bridge, with the third floor walkway offset several meters from the others. Construction difficulties resulted in a subtle but flawed design change that doubled the load on the connection between the fourth floor walkway support beams and the tie rods carrying the weight of both walkways. This new design was barely adequate to support the dead load weight of the structure itself, much less the added weight of the spectators. The connection failed, and the fourth-floor walkway collapsed onto the second-floor walkway. Both walkways then fell to the lobby floor below, resulting in 111 deaths at the scene and 219 injuries. Three additional victims died after being transported to hospitals, bringing the total number of deaths to 114.
The rescue operation lasted 14 hours and was performed by many emergency personnel, including crews from 34 fire trucks and EMS units and doctors from five local hospitals. Additional volunteers arrived from every quarter, including construction companies and building supply stores, bringing "hydraulic jacks, acetylene torches, compressors and generators." Kansas City's natural disaster response team, known as "Operation Bulldozer," was also summoned to the scene with earthmoving equipment, but was quickly sent away to make room for cranes that would lift the sections of walkway off the trapped survivors. Dr. Joseph Waeckerle, former chief of Kansas City's emergency medical system, directed the rescue effort  establishing a makeshift morgue in a ground floor exhibition area, using the hotel's taxicab driveway as a triage area and helping to organize the wounded by greatest need for medical care. Those people who could walk were instructed to leave the hotel to simplify the rescue effort; those mortally injured were told they were going to die and given morphine. Often, rescuers had to dismember bodies in order to reach survivors among the wreckage. One victim's right leg was trapped under an I-beam and had to be amputated by a surgeon, a task which was completed with a chain saw.
One of the great challenges of the rescue operation was that the hotel's sprinkler system had been severed by falling debris, flooding the lobby and putting trapped survivors at great risk of drowning. As the pipes were connected to water tanks, not a public source, the flow could not be stopped. Mark Williams, the last person rescued alive from the rubble, spent more than nine and a half hours pinned underneath the lower skywalk with both of his legs pulled out of their sockets. Williams nearly drowned before Kansas City's fire chief realized that the hotel's front doors were trapping the water in the lobby. On his orders, a bulldozer was sent to break through the doors, which allowed the water to pour out of the lobby and thus eliminated the danger to the trapped. A fire hose was then placed over the broken pipe, redirecting the water outside the hotel. Additionally, the lobby was filled with concrete dust, and visibility was poor as the emergency workers had cut the power to prevent fires.
Twenty-nine people were rescued from the rubble.
Three days after the disaster, Wayne G. Lischka, an architectural engineer hired by The Kansas City Star newspaper, discovered a significant change of the original design of the walkways. Reportage of the event later earned the Star and its associated publication the Kansas City Times a Pulitzer Prize for local news reporting in 1982. Radio station KJLA would later earn a National Associated Press award for its reporting on the night of the disaster.
The two walkways were suspended from a set of 1.25 in (32 mm) diameter steel tie 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 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 to the ceiling. Investigators determined eventually that this design supported only 60 percent of the minimum load required by Kansas City building codes.
Havens Steel Company, the contractor responsible for manufacturing the rods, objected to the original plan of Jack D. Gillum and Associates, since it required the whole of the rod below the fourth floor to be screw threaded in order to screw on the nuts to hold the fourth floor walkway in place. These threads would probably have been damaged and rendered unusable as the structure for the fourth floor was hoisted into position with the rods in place. Havens therefore proposed an alternate plan in which two separate sets of tie rods would be used: one connecting the fourth floor walkway to the ceiling, and the other connecting the second floor walkway to the fourth floor walkway.
This design change would prove 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 were required to support both the fourth floor walkway and the second floor walkway hanging from it. With the load on the fourth-floor beams doubled, Havens' proposed design could bear only 30 percent of the mandated minimum load (as opposed to 60 percent for the original design).
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. 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 between the two C-channels which had been welded together.
Investigators concluded that the basic problem was a lack of proper communication between Jack D. Gillum and Associates and Havens Steel. In particular, the drawings prepared by Jack D. Gillum and Associates were only preliminary sketches but were interpreted by Havens as finalized drawings. Jack D. Gillum and Associates failed to review the initial design thoroughly, and accepted Havens' proposed plan without performing basic calculations that would have revealed its serious intrinsic flaws — in particular, the doubling of the load on the fourth-floor beams.
The engineers employed by Jack D. Gillum and Associates who had approved the final drawings were convicted by the Missouri Board of Architects, Professional Engineers, and Land Surveyors of gross negligence, misconduct and unprofessional conduct in the practice of engineering; they all lost their engineering licenses in the states of Missouri and Texas and their membership with ASCE. Although the company of Jack D. Gillum and Associates was discharged of criminal negligence, it lost its license to be an engineering firm.
At least $140 million was awarded to victims and their families in both judgments and settlements in subsequent civil lawsuits; a large amount of this money was from Crown Center Corporation, a wholly owned subsidiary of Hallmark Cards which was the owner of the hotel real estate (like many hoteliers, Hyatt operates hotels for a fee as a management company, and does not usually own the real estate). Life and health insurance companies likely absorbed even larger uncompensated losses in policy payouts.
The Hyatt tragedy remains a classic model for the study of engineering ethics and errors (as well as disaster management). As an engineer of record for the Hyatt project, Jack D. Gillum (b. 21 November 1928, d. 4 July 2012) occasionally shared his experiences at engineering conferences in the hope of preventing future mistakes.
After the disaster, the lobby was reconstructed with only one crossing on the second floor. Unlike the previous walkways, the new bridge is supported by several columns underneath it rather than being suspended from the ceiling. As a result, some floors of the hotel now have disconnected sections on opposite sides of the atrium, so it is necessary to go to the third floor to get to the other side.
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 took his own life due to the stress.
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. The hotel's owner announced a $13-million renovation as part of its re-flagging to the Sheraton brand completed in 2012.
The tragedy is not marked in any way in the hotel. In 2008, the Skywalk Memorial Foundation announced a fundraising campaign to build a garden and a fountain in Washington Square Park, about a block from the hotel, commemorating the event. Hallmark Cards had pledged $25,000 and the city has offered $200,000. A Korean War memorial is now planned for the park and in May 2009 city officials said they were considering locating the memorial in Hospital Hill Park at 22nd Street and Gillham Road. On July 17, 2011, the 30th anniversary of the collapse, The Skywalk Memorial Foundation unveiled the design for a memorial that is to be erected in Hospital Hill Park on 22nd and Gillham across the street from the Sheraton. Permission had officially been given by Hyatt and by Hallmark Cards to erect the memorial. In 2011, Hyatt Hotels informed the Skywalk Memorial Foundation that it would not contribute to a memorial fund because the hotel is no longer managed by Hyatt and has become a Sheraton hotel. Sheraton and its parent company, Starwood Hotels and Resorts, decided to donate $5,000 towards the cost of the memorial, releasing a statement that said, "Sheraton and Starwood are very aware and respectful of Kansas City’s deep ties to this hotel and want to be a part of the effort to honor the victims, survivors, first responders and family members of the 1981 tragedy."