Miami — The contractors that designed and built the Florida International University bridge that collapsed in March have been cited by federal authorities for several “serious” safety violations and face tens of thousands of dollars in fines.

The companies failed to provide workers with a proper safety line and did not remove workers from the area despite the bridge developing cracks of “significant width, depth and length at critical locations,” according to a series of citations issued on Tuesday by the U.S. Occupational Safety and Health Administration.

The FIU bridge collapsed on March 15 while it was still under construction over Southwest Eighth Street, killing five motorists below and a worker, Navaro Brown, who had been standing atop the span. An additional five workers were seriously injured.

Footage of the accident captured the awful moment when the bridge fell. One worker, clearly visible, is seen briefly suspended in mid-air before tumbling toward the ground.

OSHA cited five companies for seven worker-safety violations, fining them a total of $86,658 in proposed penalties. The companies are designer FIGG Bridge Engineers; builder Munilla Construction Management; Bolton Perez & Associates, which provided engineering and inspection services; Structural Technologies, which specializes in post-tensioning work on bridges; and a concrete contractor, the Structural Group of South Florida. (That last company, based in Homestead, doesn’t appear to be connected in corporate records to Structural Technologies, a national firm.)

“Collectively, these employers failed to take appropriate action and provide the necessary protections to their employees while they were working on the bridge on the day it collapsed,” OSHA regional administrator Kurt A. Petermeyer said in a statement.