Photo by Robert Hernandez, courtesy Miami-Dade Fire Rescue
The five-story structure at Miami Dade College, estimated to have been 90% complete, suffered a sudden progressive collapse near midday of Oct. 10.
Photo by Robert Hernandez, courtesy Miami-Dade Fire Rescue
Crews with Miami-Dade Fire Rescue discovered the last buried worker five days after the building collapse.

A section of a $22.5-million parking garage project under construction near Miami collapsed without warning on Oct. 10, killing four construction workers. While refusing to speculate on a cause, the project's general contractor vowed to assist federal safety investigators in a "thorough, transparent finding of fact."

Near midday, the five-story structure at Miami Dade College in Doral, Fla., suffered a sudden progressive collapse, giving those inside just seconds to escape. The collapsed section represented roughly a quarter of the 520,000-sq-ft project, and was estimated to be 90% complete, according to Bill Byrne, president of Ajax Building Corp., Midway, Fla., the general contractor.

Ajax's insurer, Liberty Mutual, has hired an unidentified investigative firm, Byrne says.

The collapse killed Carlos Hurtado de Mendoza, 48, and Jose Calderon, 60, but Samuel Perez, 53, was discovered alive. He was so severely trapped that rescue workers had to amputate both of his legs to extricate him, and he later died at the hospital.

On Oct. 15, authorities found another dead worker, believed to be Robert Budhoo, 53, who had been reported missing. According to media reports, authorities stated that it could take days to recover and officially identify the body.

Prior to collapse, workers were erecting a spandrel beam on the fifth floor of the precast concrete structure, which featured double-T beams for the deck and precast columns, Byrne says. The spandrel beam was still connected to a crawler crane after the collapse, with no signs of failure. Byrne says the crane was not being viewed as a contributing factor.

Harvard Jolly, St. Petersburg, Fla., was the project's architect, and Bliss & Nyitray of Miami provided structural engineering for the building's foundations and miscellaneous steel roof and support members. According to Ajax, Coreslab Structures, a precast firm with offices in Medley, Fla., provided the precast concrete; and Coreslab Engineering Group was the engineer for the precast design. All three firms declined to answer questions from ENR.

The project's erector, identified by Ajax officials as Solar Erector, could not be reached for comment.

Byrne says the collapse occurred with "no warning whatsoever," adding that the project had been proceeding smoothly.

"It [had] really been a good project," Byrne told ENR. "We've got a great team. Everybody was working together well, and the inspections were all going very well. I really don't have any indication there were any issues whatsoever."