**7.4 Hyatt Regency Hotel skywalk failure**

The Hyatt Regency Hotel in Kansas City, Missouri, suffered a structural collapse in July 1981, in which two overhead walkways, **Figure 10**, failed under the loading of a large number of people. 114 people were killed and 216 injured. The primary cause of the failure was the induced vibrations from a number of people on the skywalks (overloaded) dancing to the rhythm of the music on the ground floor. It was the worst civil engineering failure in US history. With about 40 people on the second-level walkway, and another 20 on the fourth floor walkway, the fourth floor walkway gave way from a failed bolt connection, dropped onto the second floor walkway, where both plunged to the atrium floor.

**Figure 10.** *Fourth and second floor skywalks falling to the atrium. CC BY-SA 3.0.*

*Failure analysis*: The root cause was the failure of the fourth floor skywalk suspension rod in a welded channel iron causing the skywalk to drop onto the second floor skywalk with both then dropping on the ground floor. Among the contributing factors was inadequate design in the skywalks, a failure in engineer review of shop drawings and field changes, a lack of oversight responsibility, and clear lines of authority starting with the Engineer of Record.
