The U.S. Department of Labor’s Occupational Safety and Health Administration is investigating a fatal workplace accident Tuesday in southwest suburban Bedford Park.

Gregory Isom, of Dolton, was directing a vehicle at 7:31 p.m. in the 6800 block of West 73rd Street when it backed over him, according to Bedford Park police.

Isom was taken to Christ Medical Center in Oak Lawn, where he was pronounced dead at 8:13 p.m., the medical examiner’s office said. An autopsy Wednesday revealed that he died from multiple blunt force injuries caused by a vehicle striking a pedestrian at a worksite. His death was ruled an accident.

OSHA has opened an investigation into the fatality, a spokesman confirmed Thursday morning. The accident also remained under investigation by Bedford Park police.