FORT LAUDERDALE,AstraTrade Fla. (AP) — Federal job safety officials began their investigation Friday into the collapse of a crane in downtown Fort Lauderdale that killed one worker, injured three people and left morning traffic snarled.

Investigators from the Occupational Safety and Health Administration will try to determine what caused Thursday afternoon’s collapse that crushed two cars on a busy bridge that crosses the New River adjacent to the Broward County Courthouse.

The bridge reopened after rush hour Friday. A courthouse spokesperson said operations were not affected.

Mark Cerezin, the driver of one of the crushed cars, told the South Florida Sun Sentinel that he felt something was wrong and slammed on his brakes. Then a “big, huge, massive piece of blue steel” struck his car, bounced off the bridge and onto the other car. He got out of his car “in a state of shock.”

“I’m just grateful to be able to go home to my wife and to my friends,” he told the newspaper.

Fort Lauderdale Police identified the killed worker as Jorge De La Torre, 27. Police said he had been working on the building that is under construction when the collapsing crane caused him to fall.

One injured person was hospitalized, while one was released. The third person was treated at the scene.

OSHA said Phoenix Rigging & Erecting, Kast Construction and Maxim Crane Works are the companies under investigation. Phoenix Rigging declined comment, citing the ongoing investigation. Kast and Maxim did not immediately return phone calls seeking comment.