While Milwaukee is abuzz about the collapse of a concrete panel at the O’Donnell Park parking structure and its resulting fatality, with the passage of time many people have forgotten -- or have never heard of -- the deadliest structural engineering failure in US history.
Before The Disaster: The Tea Dance
On July 17, 1981, the Hyatt Regency Hotel in Kansas City, Missouri, held a videotaped tea-dance party in their atrium lobby. With many party-goers standing and dancing on the suspended walkways, connections supporting the ceiling rods that held up the second and fourth-floor walkways across the atrium failed, and both walkways collapsed onto the crowded first-floor atrium below. The fourth-floor walkway collapsed onto the second-floor walkway, while the offset third-floor walkway remained intact. As the United States' most devastating structural failure, in terms of loss of life and injuries, the Kansas City Hyatt Regency walkways collapse left 114 dead and in excess of 200 injured. In addition, millions of dollars in costs resulted from the collapse, and thousands of lives were adversely affected. The hotel had only been in operation for approximately one year at the time of the walkways collapse.
From the AP:
Sally Firestone went to the Friday night tea dance with three friends after work. She was all dolled up, standing on a suspended walkway at the Hyatt Regency downtown, enjoying a dance contest in the hotel lobby below. The last thing she remembers is hearing a loud "crack." ...
At 7:04 p.m., the band started playing Duke Ellington's "Satin Doll" as a dance contest got under way. About a minute later, the fourth-floor walkway split in two places near the center, falling down onto the second-story walkway, which also collapsed.
The Fourth Floor Walkway Was Suspended Directly Over The Second Floor Walkway, With The Third Floor Walkway Offset To The Side Several Meters
From the AP:
Rescue workers spent the next 14 hours pulling victims, dead and alive, from the tangle of steel and concrete. Cranes and forklifts moved heavy slabs of concrete so emergency crews could reach the injured. A firefighter performed an on-the-spot amputation with a chain saw to free one victim. City buses lined up outside to cart the walking wounded to hospitals. Sally Firestone lay unconscious and trapped for hours under the debris. The most severely injured of the survivors, she was left a quadriplegic with no feeling below her shoulders
Woman Victim Under The Rubble
The failure of the Hyatt Regency walkway was a combination of things. The most important cause was the design in the walkways. Due to disputes between G.C.E. and Havens, the design changed from a single to a double hanger rod, simply because Havens did not want to thread the entire rod in order to install the washer and nut. Due to the addition of another rod, the load on the nut connecting the fourth floor segment was increased. The original load for each hangar rod was to be 90kN, but the alteration increased the load to 181kN. The box beams were welded horizontally and therefore could not hold the weight of two walkways. During the collapse, the box beam split and the bottom rod pulled through the box beam resulting in the collapse.
Left: Proposed Design Right: Actual Design
Both designs of the walkways were well below the required safety stress required by the Kansas City Building Code. Take a look at the beam for the third-floor walkway, which did not collapse.
The Hyatt tragedy remains a classic model for the study of engineering ethics and errors. Gillum's chief engineer continues to share his experiences with others, in the hope that the mistakes which led to the Hyatt disaster will not be repeated. 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 second floor to get to the other side. The hotel later reopened, and has been renamed Hyatt Regency Crown Center. It has since been renovated and now serves as one of the city's most luxurious hotels.
The New Walkway
You can watch Seconds From Disaster - Skywalk Collapse on YouTube.
The largest settlement -- about $12 million of the estimated $140 million total -- went to Sally Firestone. Her thoughts:
"I'm not really bitter. I'm just amazed that no one discovered the problems with the building," said Firestone, who lives in a retirement home in south Kansas City and requires around-the-clock care. "So many things happened along the way that should have been caught."
Sally Firestone Today
I knew Sally Firestone a long time ago, so her reaction does not surprise me. Her father, Rev. Jesse Firestone (a good man, I might add) was the pastor at the First United Methodist Church in my old hometown of Belvidere, Illinois. Although she would be the last one to ask, you might want to keep her in your thoughts and prayers, OK?