The Kansas City Hyatt Regency Walkway Collapse

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The Kansas City Hyatt Regency Walkway Collapse

• The Worst Structural Disaster In the United
  States

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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

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Background Of Walkway

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

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Walkways Original Design

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

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Walkway as Constructed

• 4th floor box beams
• -Ends had 2 holes
• -Outer hole connected to ceiling
• -2 lower rods went through inner holes to
  support second floor walkway

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July 17, 1981

• 705pm, July 17, 1981
• 2nd and 4th floor walkways collapsed.
• Atrium filled with 1600 people during party
• 2nd and 4th floor walkway dropped from hangers
• 114 killed, 200 injured

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Why did this fail?
Original Design
As Constructed
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Reason for Failure

• Original design
• Box beams of 4th floor walkway designed to only
  carry the load of itself
• As constructed
• Box beam of 4th floor carried load of itself and
  2nd floor

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Other Factors

• Resonating vibrations from dancing and music
• Greatly increased stress on box beams.
• Kansas City Building Code required for walkway
• 100lbs/ft2 or 72,000 lbs for each walkway
• Actual load day of tragedy
• 9450 lbs (63 people _at_150lbs each)
• Design Lacked Redundancy

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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
• Didnt notice essential difference in 2 designs
• Licenses revoked in Missouri

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• It wasnt 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.