1. The Kansas City Hyatt Regency Walkway Collapse “The Worst Structural Disaster In the United States”

2. The Kansas City Hyatt Regency Walkway Collapse Dawn Williams – Background Timmy Velander – Design Mike Tillges – Walkway Collapse Andy Ungerman – Reasons for Failure Ben Volkmann – Other Factors Brad Tucker – Effects

3. Background Of Walkway July 1980 – Most Modern Hotel in Kansas City finished. Consisted of 3 Buildings, 2 were connected by 3 walkways.

4. Walkway’s Original Design Box beams as intermediate supports One hole at both ends of Flanges Threaded single rod -Hanger for 2 nd and 4 th floor walkways (3 rd floor walkway was separate entity)

5. Walkway as Constructed 4 th floor box beams: -Ends had 2 holes -Outer hole connected to ceiling -2 lower rods went through inner holes to support second floor walkway

6. July 17, 1981 7:05pm, July 17, 1981 2 nd and 4 th floor walkways collapsed. Atrium filled with 1600 people during party 2 nd and 4 th floor walkway dropped from hangers 114 killed, 200 injured

9. Why did this fail? Original DesignAs Constructed

11. Reason for Failure Original design: Box beams of 4 th floor walkway designed to only carry the load of itself As constructed: Box beam of 4 th floor carried load of itself and 2 nd floor

12. Other Factors Resonating vibrations from dancing and music Greatly increased stress on box beams. Kansas City Building Code required for walkway: 100lbs/ft 2 or 72,000 lbs for each walkway Actual load day of tragedy 9450 lbs (63 people @150lbs each) Design Lacked Redundancy

13. Effects 114 killed, 200 injured Lawsuits tallied more that $ 3 billion Original design did not meet code, but might not have collapsed Fault found with design engineers Didn’t notice essential difference in 2 designs Licenses revoked in Missouri

14. “It wasn’t a matter of doing something wrong, they just never did it at all. Nobody ever did any calculations…. It got built without anybody figuring out if it would be strong enough.” Patrick McLarny, attorney representing state of MO.