Kansas City Hyatt Regency Walkway Collapse

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Kansas City Hyatt RegencyWalkway Collapse

• AME30362 Design Methodology, Spring 2006

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An Engineer's Responsibility

• Engineers have a tremendous responsibility to
  insure the safety, health, and welfare of the
  public.
• The public well-being can be maintained only if
  engineers follow all codes and standards, and
  uphold their professional obligations.
• Safety during the construction phase of projects
  will help to insure the ultimate safety of the
  completed structure.
• The Kansas City Hyatt Regency Walkway Collapse is
  an incident where construction safety was
  compromised, leading to the eventual collapse of
  the walkway.

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Walkway Collapse

• On July 17, 1981, the Hyatt Regency Hotel in
  Kansas City, Missouri held a videotaped tea-dance
  party in their atrium lobby. The hotel had only
  been open for approximately one year.
• Many people were standing and dancing on the
  suspended walkways.
• Several of the walkways collapsed, resulting in
  114 people killed, and over 200 injured. Millions
  of dollars in costs resulted from the collapse.

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Walkway Collapse (cont.)

• The 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.

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Basic Walkway Design

• Three walkways, on the second, third, and fourth
  floors, span the atrium.
• The third floor walkway was designed for higher
  traffic than the other walkways, and was
  consequently wider and offset from the other
  walkways.
• The third and fourth floor walkways were
  suspended from the atrium roof, with the second
  floor walkway connected to the fourth floor
  walkway.

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A Collapse During Construction

• A collapse occurred on October 14, 1979 while the
  hotel was under construction.
• Over 2700 square feet of the atrium roof
  collapsed because a roof connection failed.
• After this collapse, the engineering firm in
  charge promised to review all steel connections
  and requested on-site representation during
  construction.
• The owner rejected the request, due to the
  additional cost involved.

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Change In Design

• While the hotel was under construction, The
  fabricator changed the design from a one-rod to a
  two-rod system to simplify the assembly task,
  doubling the load on the connector, which
  ultimately resulted in the walkway collapse.

Initial Design
New Design
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Change In Design (cont.)

• The fabricator did not want to have to thread the
  entire rod in
• order to install the washer and the nut. The
  revised design
• consisted of
• The top ends of the third and fourth floor
  support rods were attached to the atrium roof.
• The bottom ends went through the box beam where a
  washer and nut were threaded on.
• A second rod was attached to the box beam four
  inches from the first rod.
• The second floor walkway was suspended from the
  fourth floor walkway in a similar fashion.

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FBD of Each Design
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Cutting Corners

• The fabricator, while in sworn testimony, claimed
  that his company had telephoned the engineering
  firm for change approval. The engineering firm
  declared they had not received the phone call.
• Even as originally designed, the walkways were
  barely capable of holding up the expected load,
  and would have failed to meet Kansas City
  building requirements.
• The Kansas City Building Code requires a minimum
  support value of 151 kN. The original design was
  capable of supporting 90 kN. With the design
  changes made during construction, the walkways
  would be supporting double that amount, or 180
  kN, assuming the walkways were loaded at the
  maximum recommended weight limit.

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Walkway Failure Mode

• The box beams could not support the applied loads
  and the fasteners on the end of the rods tore
  through the seam in the box beams, leading to the
  collapse.

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Who was responsible?

• A lack of communication between the designer and
  the fabricator is one of the contributors to the
  failure of the walkways.
• The engineering firm did receive revised drawings
  during construction and stamped them with their
  engineering review seal, authorizing
  construction.
• The revised design was significantly less capable
  of holding up the required forces, and was not
  designed in accordance with the Kansas City
  building code.

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Consequences

• 114 people were killed and over 200 injured.
• Many principals involved lost engineering
  licenses.
• Engineers were found guilty of gross negligence,
  misconduct, and unprofessional conduct in the
  practice of engineering.
• Expensive legal suits were settled out of court.
• Several firms involved went bankrupt.

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Conclusion

• From the Kansas City example, the importance of
  an engineer's responsibility can be seen in
  aspects ranging from design to construction.
• The collapse of the atrium roof during
  construction was indicative of problems with the
  overall design.
• Engineers should thoroughly review all designs
  and modifications made during the construction
  phase to insure the safety of the project.