Trinity College SS 3A6 Report
Hyatt Regency Walkway Collapse
Date of Submission: 24th October 2008
Group 3.
John Norris
Simon Jones
Jonathan Clarke
Brían Cooney
LECTURER: Dermot O’Dwyer
An Introduction
The Hyatt Regency walkway collapse was a major
structural disaster that happened in July 17th 1981, in
Kansas City, United States of America. In 1980 a new 40storey hotel with a tower and conference facilities, which
were connected by a huge open concept atrium (4 storeys
high) was built. The atrium featured a multistory atrium
criss-crossed by suspended concrete walkways on the
second, third, and fourth levels, with the fourth level
walkway directly above the second level walkway. The
third floor walkway was set off to the side several meters
away from the other two and was not affected as you can
see in the photograph below.
Thousands of people had gathered in the atrium to
participate in, and watch a dance contest. That night the 3
walkways were packed with visitors as they watched over
the active lobby which was the dance floor. At 7:05 p.m.,
a loud crack was heard as the second and fourth floor
walkways came crashing down to the ground level. A
massive loss of life was incurred which totalled to 114
deaths and 200+ injuries.
Construction Type
Construction issues led to a subtle but flawed design
change that doubled the load on the box-beam connection
between the fourth floor walkway and the tie rods carrying
the weight of the second floor walkway. The new design
could barely handle the dead load weight of the structure
itself; with the imposed load of all the spectators on added
to that that it hadn’t a chance.
The Design
The original design by Jack D. Gillum and Associates called for
three pairs of rods running from the second floor cross-beams
directly all the way to the ceiling. Investigators eventually
determined that this design could only support 60% of the
minimum load required by Kansas City building codes.
The contractor responsible for manufacturing the rods, Havens
Steel Company, objected to the original plan,
since it required the whole of the rod below
the fourth floor to be threaded, and threaded through the box-beam in order to
screw on the nuts to hold the fourth floor walkway in place. Havens’ new design
was to tie directly the floor 2 walkway to the floor 4 walkway. This resulted in
putting extra pressures on the supporting beam holding the floor 4 walkway to
the ceiling.
New Design
Failure of the supporting washer
Extent of Damage
Here is a photograph of the extent of damage
to the walkways which fell to the ground floor.
The design failed because of the addition of
an extra supporting rod. The extra rod
increased the load on the fourth floor nut
from 90 kN to 181 kN. The box beams were
longitudinally welded as had originally
proposed. Because of this they could not hold
the weight of the two walkways. During the
collapse, the box beam split and the support
rods pulled through them. As shown in the
photograph below.
Conclusions
The Missouri Board of Architects, Professional Engineers, and Land Surveyors convicted the
engineers employed by Jack D. Gillum and Associates who had signed off on the final drawings of
gross negligence, misconduct, and unprofessional conduct in the practice of engineering; all the
members involved lost their engineering licenses in the states of Missouri and Texas and their
membership to ASCE (American Society of Civil Engineers). While Jack D. Gillum and Associates
itself was cleared of criminal negligence, it was stripped of its license to be an engineering firm.Law
suits followed and at least $140 million was awarded to victims and their families in both
judgments and settlements. a large amount of this money came from Crown Center Corporation.
An engineer has a responsibility to the public to ensure that they take all reasonable steps to
ensure their design is sound. In the case of the Hyatt Regency walkway collapse the engineers did
not undertake a sufficient review of the new design to the rod/box beam connection and this led to
a large loss of life. As a result engineers became fully responsible for design projects in the US. The
engineer must remember how important it is to review thoroughly all design modifications during
the construction phase of any project. Disasters such as these are a reminder of how an error in
judgement can or negligence can lead to such a large loss of life.
Information gathered from:
http://ethics.tamu.edu/ethics/hyatt/hyatt2.htm
http://en.wikipedia.org/wiki/Hyatt_Regency_walkway_collapse