On This Date: What Caused The Hartford Civic Center Roof Collapse?

HARTFORD, CT — It was 46 years ago this morning that most of Connecticut woke up to find out a near-disaster had occurred in the capital city of Hartford. Just hours after completion of a college basketball game, attended by nearly 5,000 fans, the roof of the Hartford Civic Center collapsed into a 1,400-ton pile of twisted steel and concrete rubble.

Fortunately, the collapse occurred shortly after 4 a.m., so the spectators who had witnessed UConn's 56-49 victory over UMass were home in their beds, and the 10,000-seat arena was empty. Had the incident taken place six hours earlier, one of the largest single-day losses of life would likely have occurred - more than the bombing of Pearl Harbor, the 9/11 terrorist attacks and the 1906 San Francisco earthquake, and only trailing the 1900 Galveston hurricane in terms of human devastation.

Instead, the city suffered deep financial wounds, as the Civic Center had been the centerpiece of a 4-part revitalization project, approved in 1972, which also included Bushnell Plaza and Constitution Plaza. The Main Street complex opened in early 1975, and contained not only the arena, known as the Veterans Memorial Coliseum, but a shopping mall that was 100 percent filled.

The building's primary tenants were the New England Whalers of the World Hockey Association, with the Boston Celtics and UConn also playing several games per season at the spacious venue. Concerts were a huge attraction at the time; in 1977 alone, the building played host to performances by Fleetwood Mac, America, Boston and Jethro Tull, and was the site of a live album recorded by the legendary Grateful Dead. Elvis Presley was scheduled to perform there on Aug. 21, 1977, but passed away five days earlier in his Graceland mansion at age 42.

For many years, a common myth was that the roof buckled under the weight of heavy snow and ice. While a storm did pass through Connecticut during the overnight hours, leaving four to five inches of new snow, subsequent investigations revealed faulty design was actually the culprit.

In a 2019 episode of "Engineering Catastrophes" on the Science Channel, bioengineer Greg Szulgit explained the then-new technology of computer-aided design (CAD) "was in its infancy," and a cutting-edge style of roof called a "space frame," measuring 300 by 360 feet, was supported by four pylons which allowed an unobstructed view for each spectator.

An official investigation found "computer calculations had seriously underestimated the weight that the roof could handle." When entering data into the computer program, engineers had failed to recalculate their numbers after a change was made in the original design.

"The computer had calculated the design based on [a] flat roof, but the roof had to be slightly pitched so the water, or in this case snow, could drain off," physicist Simon Foster said.

Failure to correct the data led to an overload on exterior bracing and led to a chain reaction of buckling that fateful night, according to structural engineer Steven Ressler.

The official investigation concluded, "The roof began progressive failure as soon as it had been installed."

Reconstruction of the Civic Center took 21 months, and it re-opened on Oct. 15, 1979. The Whalers remained the primary tenant until moving to North Carolina in 1997. Today, the renamed XL Center is home to the Hartford Wolf Pack, the American Hockey League affiliate of the New York Rangers, and occasionally hosts basketball games, concerts and expos.