The U.S. Department of Labor’s Occupational Safety and Health Administration is investigating the death of a worker who fell from the roof of a building Wednesday afternoon in the Southwest Side Ashburn neighborhood.

Martin Hrdlicka, 42, appears to have accidentally fallen from the roof about 1 p.m. in the 2800 block of West Columbus Avenue, according to Chicago Police and the Cook County medical examiner’s office. A coworker found him lying on the ground, tried to provide first aid, then called 911.

He was taken to Holy Cross Hospital, where he was pronounced dead at 1:28 p.m., authorities said. An autopsy Thursday found he died of multiple injuries caused by a fall from height, and his death was ruled an accident.

Hrdlicka, who worked for a roofing company called STA Enterprises Inc., fell about 35 feet while performing roof repairs, according to OSHA spokesman Scott Allen. The company was hired by the building’s owner, and crews had been working at the site for two to three weeks.

“OSHA found no evidence of fall protection in place at the site,” Allen said Thursday morning. “OSHA has opened an investigation with STA Enterprises.”

A spokesperson for STA Enterprises, based in west suburban Big Rock, declined to comment on the incident Thursday morning.