The Hyatt Regency Walkways
The Hyatt Regency in downtown Kansas City was plagued with difficulties during its construction, including the collapse of a section of its roof over the atrium in 1979, an event which was attributed to a structural failure. When the hotel opened in 1980, it was acclaimed for its lobby space, which featured an open atrium of several stories in height, crossed by walkways which connected the open spaces of the hotel’s wings with walkways on the second, third, and fourth floors, which from the lobby floor beneath appeared as dramatic views. The fourth floor walkway was directly above that of the second.
The walkways were constructed of reinforced concrete, steel, and glass. They were about 120 feet in length, spanning the lobby below. Each weighed about 32 tons. The third and fourth floor walkways were suspended from the ceiling, with the second floor walkway suspended from the fourth floor walkway which ran directly above it, a modification from the original plan which was adopted during construction. It meant that the rods which supported the fourth floor walkway were actually supporting two walkways, which exceeded the limits of their design. The support beams underneath the fourth floor walkway (which were connected by suspenders from the ceiling) were supporting both floors.
The hotel had been open for just over one year when a tea dance was held in the atrium on July 17, 1981. The activities in the atrium drew the attention of many of the guests in the hotel, and each of the suspended walkways held spectators who paused on them to view the activities below. About 40 people were gathered on the second floor walkway, with another fifteen to twenty on the fourth floor walkway directly above. The third floor walkway was crowded as well. Witnesses later reported hearing several snapping noises before the second and fourth floor walkways plunged to the atrium floor.
There were 114 total deaths and 219 injuries. It took more than 14 hours to extricate all of the dead and injured from the scene, which required the support of volunteers from local construction companies and the use of cranes to remove the walkways. In addition to the more than sixty tons of debris on top of the victims, the entire atrium was drenched from the hotel’s sprinkler system, which had been broken by the fall of the walkways and distributed its contents onto the atrium floor. The front doors of the hotel sealed the water in the lobby, and it continued to rise during the rescue operation, the sprinklers being connected to water tanks rather than the city supply main.
The investigation determined that the modification made to the design during construction led to the fourth floor walkway support beams being barely able to support the weight of the fourth floor walkway, and the additional demand to support the second floor walkway ensured that the system would fail, as it did. The third floor walkway was removed and a second floor walkway, supported by columns rather than suspension, was added when the atrium was rebuilt. It was later revealed that the modification which led to the catastrophic failure of the support system was discussed and approved in a telephone call, without reference to drawings or specifications.