Hyatt Regency walkway collapse - AbsoluteAstronomy.com

The Hyatt Regency hotel walkway collapse was a collapse of an interior suspended skywalk system that occurred on July 17, 1981, in Kansas City

Kansas City, Missouri

Kansas City, Missouri is the largest city in the U.S. state of Missouri and is the anchor city of the Kansas City Metropolitan Area, the second largest metropolitan area in Missouri. It encompasses in parts of Jackson, Clay, Cass, and Platte counties...

, Missouri, United States, killing 114 people and injuring 216 others during a tea dance

Tea dance

A tea dance, or thé dansant is a summer or autumn afternoon or early-evening dance from four to seven, sometimes preceded in the English countryside by a garden party. The function evolved from the concept of the afternoon tea, and J. Pettigrew traces its origin to the French colonization of Morocco...

. At the time, it was the deadliest structural collapse in U.S. history.

Background

Construction of the 40-story Hyatt Regency Kansas City began in 1978, and the hotel opened on July 1, 1980, after construction delays, including an incident on October 14, 1979, when 2700 square feet (250.8 m²) of the atrium roof collapsed because one of the roof connections on the north end of the atrium failed.

The walkway collapse was the second major structural failure

Structural failure

Structural failure refers to loss of the load-carrying capacity of a component or member within a structure or of the structure itself. Structural failure is initiated when the material is stressed to its strength limit, thus causing fracture or excessive deformations...

in Kansas City in just over two years. On June 4, 1979, the roof of the unoccupied Kemper Arena

Kemper Arena

Kemper Arena is a 19,500 seat indoor arena, in Kansas City, Missouri.It is named for R. Crosby Kemper Sr., a member of the powerful Kemper financial clan and who donated $3.2 million, from his estate for the arena...

collapsed without loss of life. The architects and engineering firms involved in the two collapses were unrelated.

One of the defining features of the hotel was its lobby, which featured a multistory atrium

Atrium (architecture)

In modern architecture, an atrium is a large open space, often several stories high and having a glazed roof and/or large windows, often situated within a larger multistory building and often located immediately beyond the main entrance doors...

spanned by steel, glass and concrete walkways on the second, third and fourth levels suspended from the ceiling. The walkways were approximately 120 ft (36.6 m) long and weighed approximately 64000 lb (29,029.9 kg). The fourth level walkway aligned directly above the second level walkway.

Disaster

On July 17, 1981, approximately 1,600 people gathered in the atrium to participate in and watch a dance competition. Dozens stood on the walkways. At 7:05 PM, the second-level walkway held approximately 40 people with more on the third and an additional 16 to 20 on the fourth level who watched the activities of crowd in the lobby below. The fourth floor bridge was suspended directly over the second floor bridge, with the third floor walkway offset several meters from the others. Construction difficulties resulted in a subtle but flawed design change that doubled the load on the connection between the fourth floor walkway support beams

Beam (structure)

A beam is a horizontal structural element that is capable of withstanding load primarily by resisting bending. The bending force induced into the material of the beam as a result of the external loads, own weight, span and external reactions to these loads is called a bending moment.- Overview...

and the tie rod

Tie rod

A tie rod is a slender structural unit used as a tie and capable of carrying tensile loads only.- Subtypes and examples of applications :* In airplane structures, tie rods are sometimes used in the fuselage or wings....

s carrying the weight of both walkways. This new design was barely adequate to support the dead load weight of the structure itself, much less the added weight of the spectators. The connection failed and the fourth floor walkway collapsed onto the second floor and both walkways then fell to the lobby floor below, resulting in 111 immediate deaths and 216 injuries. Three additional victims died after being evacuated to hospitals making the total number of deaths 114 people.

The rescue operation lasted fourteen hours and was performed by many emergency personnel, including crews from 34 fire trucks and EMS units, doctors from five local hospitals and construction crews with heavy equipment. Dr. Joseph Waeckerle, former chief of Kansas City's emergency medical system, directed the rescue effort establishing a makeshift morgue in a ground floor exhibition area, using the hotel's taxicab driveway as a triage

Triage

Triage or ) is the process of determining the priority of patients' treatments based on the severity of their condition. This rations patient treatment efficiently when resources are insufficient for all to be treated immediately. The term comes from the French verb trier, meaning to separate,...

area and helping to organize the wounded by greatest need for medical care. Those people who could walk were instructed to leave the hotel to simplify the rescue effort; those mortally injured were told they were going to die and were given morphine

Morphine

Morphine is a potent opiate analgesic medication and is considered to be the prototypical opioid. It was first isolated in 1804 by Friedrich Sertürner, first distributed by same in 1817, and first commercially sold by Merck in 1827, which at the time was a single small chemists' shop. It was more...

. Workmen from a local construction company were also hired by the city fire department, bringing with them cranes, bulldozers, jackhammers and concrete-cutting power saws.

The greatest challenge of the rescue operation was due to the fact that the hotel's water pipes had been severed by falling debris, flooding the lobby and putting trapped survivors at great risk of drowning. As the pipes were connected to water tanks, not a public source, the flow could not be shut. Mark Williams, the last person rescued alive from the rubble, spent more than nine and a half hours pinned underneath the lower skywalk, both legs pulled out of their sockets. Williams nearly drowned before Kansas City's fire chief realized that the hotel's front doors were trapping the water in the lobby. On his orders, a bulldozer was sent to break through the doors, which allowed the water to pour out of the lobby and thus eliminated the danger to the trapped.

Twenty-nine people were rescued from the rubble.

Investigation

Three days after the disaster, Wayne Lischka, a structural engineer

Structural engineering

Structural engineering is a field of engineering dealing with the analysis and design of structures that support or resist loads. Structural engineering is usually considered a specialty within civil engineering, but it can also be studied in its own right....

hired by The Kansas City Star
The Kansas City Star
The Kansas City Star is a McClatchy newspaper based in Kansas City, Missouri, in the United States. Published since 1880, the paper is the recipient of eight Pulitzer Prizes...

newspaper

Newspaper

A newspaper is a scheduled publication containing news of current events, informative articles, diverse features and advertising. It usually is printed on relatively inexpensive, low-grade paper such as newsprint. By 2007, there were 6580 daily newspapers in the world selling 395 million copies a...

, discovered a significant change of the original design of the walkways. Reportage of the event later earned the Star and its associated publication the Kansas City Times
Kansas City Times
The Kansas City Times was a morning newspaper in Kansas City, Missouri, that was published from 1867 to 1990.The morning Kansas City Times, under ownership of afternoon The Kansas City Star, won two Pulitzer Prizes and was actually bigger than its parent when its name was changed to the...

a Pulitzer Prize

Pulitzer Prize

The Pulitzer Prize is a U.S. award for achievements in newspaper and online journalism, literature and musical composition. It was established by American publisher Joseph Pulitzer and is administered by Columbia University in New York City...

for local news reporting in 1982. (Radio station KJLA-AM won a National Associated Press award for its reporting on the night of the disaster.)

The two walkways were suspended from a set of 1.25 inch diameter steel

Structural steel

Structural steel is steel construction material, a profile, formed with a specific shape or cross section and certain standards of chemical composition and mechanical properties...

tie rod

Tie rod

s, with the second floor walkway hanging directly under the fourth floor walkway. The fourth floor walkway platform was supported on 3 cross-beams suspended by steel rods retained by nut

Nut (hardware)

A nut is a type of hardware fastener with a threaded hole. Nuts are almost always used opposite a mating bolt to fasten a stack of parts together. The two partners are kept together by a combination of their threads' friction, a slight stretch of the bolt, and compression of the parts...

s. The cross-beams were box girder

Box girder

A box or tubular girder is a girder that forms an enclosed tube with multiple walls, rather than an or H-beam. Originally constructed of riveted wrought iron, they are now found in rolled or welded steel, aluminium extrusions or pre-stressed concrete....

s made from C-channel strips welded together lengthwise, with a hollow space between them. The original design by Jack D. Gillum and Associates specified three pairs of rods running from the second floor to the ceiling. Investigators determined eventually that this design supported only 60 percent of the minimum load required by Kansas City building code

Building code

A building code, or building control, is a set of rules that specify the minimum acceptable level of safety for constructed objects such as buildings and nonbuilding structures. The main purpose of building codes are to protect public health, safety and general welfare as they relate to the...

s.

Havens Steel Company, the contractor responsible for manufacturing the rods, objected to the original plan of Jack D. Gillum and Associates, since it required the whole of the rod below the fourth floor to be screw thread

Screw thread

A screw thread, often shortened to thread, is a helical structure used to convert between rotational and linear movement or force. A screw thread is a ridge wrapped around a cylinder or cone in the form of a helix, with the former being called a straight thread and the latter called a tapered thread...

ed in order to screw on the nuts to hold the fourth floor walkway in place. These threads would probably have been damaged and rendered unusable as the structure for the fourth floor was hoisted into position with the rods in place. Havens therefore proposed an alternate plan in which two separate sets of tie rods would be used: one connecting the fourth floor walkway to the ceiling, and the other connecting the second floor walkway to the fourth floor walkway.

This design change would prove fatal. In the original design, the beams of the fourth floor walkway had to support only the weight of the fourth floor walkway itself, with the weight of the second floor walkway supported completely by the rods. In the revised design, however, the fourth floor beams were required to support both the fourth floor walkway and the second floor walkway hanging from it. With the load on the fourth-floor beams doubled, Havens' proposed design could bear only 30 percent of the mandated minimum load (as opposed to 60 percent for the original design).

The serious flaws of the revised design were compounded by the fact that both designs placed the bolts directly through a welded joint connecting two C-channels, the weakest structural point in the box beams. Photographs of the wreckage show excessive deformations of the cross-section. During the failure the box beams split along the weld and the nut supporting them slipped through the resulting gap between the two C-channels which had been welded together.

Investigators concluded that the basic problem was a lack of proper communication between Jack D. Gillum and Associates and Havens Steel. In particular, the drawings prepared by Jack D. Gillum and Associates were only preliminary sketches but were interpreted by Havens as finalized drawings. Jack D. Gillum and Associates failed to review the initial design thoroughly, and accepted Havens' proposed plan without performing basic calculations that would have revealed its serious intrinsic flaws — in particular, the doubling of the load on the fourth-floor beams.

Aftermath

The engineers employed by Jack D. Gillum and Associates who had approved the final drawings were convicted by the Missouri Board of Architects, Professional Engineers, and Land Surveyors of gross negligence, misconduct and unprofessional conduct in the practice of engineering; they all lost their engineering license

Professional Engineer

Regulation of the engineering profession is established by various jurisdictions of the world to protect the safety, well-being and other interests of the general public, and to define the licensure process through which an engineer becomes authorized to provide professional services to the...

s in the states of Missouri and Texas and their membership with ASCE

American Society of Civil Engineers

The American Society of Civil Engineers is a professional body founded in 1852 to represent members of the civil engineering profession worldwide. It is the oldest national engineering society in the United States. ASCE's vision is to have engineers positioned as global leaders who strive toward...

. While Jack D. Gillum and Associates itself was discharged of criminal negligence

Criminal negligence

In the criminal law, criminal negligence is one of the three general classes of mens rea element required to constitute a conventional as opposed to strict liability offense. It is defined as an act that is:-Concept:...

, it lost its license to be an engineering firm.

At least $140 million was awarded to victims and their families in both judgments and settlements in subsequent civil law

Civil law (common law)

Civil law, as opposed to criminal law, is the branch of law dealing with disputes between individuals or organizations, in which compensation may be awarded to the victim...

suits; a large amount of this money was from Crown Center Corporation, a wholly owned subsidiary of Hallmark Cards

Hallmark Cards

Hallmark Cards is a privately owned American company based in Kansas City, Missouri. Founded in 1910 by Joyce C. Hall, Hallmark is the largest manufacturer of greeting cards in the United States. In 1985, the company was awarded the National Medal of Arts....

which was the owner of the actual hotel real estate (like many hoteliers, Hyatt operates hotels for a fee as a management company, and does not usually own the hotel real estate). Life and health insurance companies probably absorbed even larger uncompensated losses in policy payouts.

The Hyatt tragedy

Tragedy (event)

A tragedy is an event in which one or more losses, usually of human life, occurs that is viewed as mournful. Such an event is said to be tragic....

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 caused 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.

Several rescuers suffered post-traumatic stress as well, and relied upon each other in an informal support group. Jackhammer operator "Country" Bill Allman took his own life due to the stress.

The hotel was renamed the Hyatt Regency Crown Center in 1987, and again the Sheraton Kansas City at Crown Center in 2011. It has been renovated numerous times since, though the lobby retains the same layout and design. It is now one of the city's most luxurious hotels.

Memorial

The accident is not marked in any way in the hotel. In 2008, the Skywalk Memorial Foundation announced a fundraising campaign to build a garden and a fountain in Washington Square Park, about a block from the hotel, commemorating the event. Hallmark Cards

Hallmark Cards

had pledged $25,000 and the city has offered $200,000. A Korean War memorial is now planned for the park and in May 2009 city officials said they were considering locating the memorial in Hospital Hill

Hospital Hill

Hospital Hill is a neighborhood in Kansas City, Missouri. The neighborhood is located between 22nd Street to 25th Street and Gillham Road to Troost Avenue. This name reflects not only the geography on which the buildings rest, but also a history of public hospitals on the same site dating back to...

Park at 22nd Street and Gillham Road

Gillham Road

Gillham Road is a major north/south main street that runs in Kansas City, Missouri from 22nd Street to 46th Street. Gillham Road becomes Gillham Plaza from 31st Street to 34th Street. This causes Gillham Road to go over one block east into a residential neighborhood...

. On July 17, 2011, the 30th anniversary of the collapse, The Skywalk Memorial Foundation unveiled the design for a memorial that is to be erected in Hospital Hill Park on 22nd and Gillham across the street from the Hyatt. Permission has now officially been given by The Hyatt and by Hallmark Cards

Hallmark Cards

to erect the memorial.

External links

Engineering Ethics - includes photos of the failed walkway components
failurebydesign.info - physics presentation and resources
Network news feature from July 23, 1981, including interviews

The source of this article is wikipedia, the free encyclopedia. The text of this article is licensed under the GFDL.

Background

Disaster

Investigation

Aftermath

Memorial

See also

Further reading

External links