The federal Occupational Safety and Health Administration is investigating after an iron worker fell to his death Monday morning at a construction site in southwest suburban Wilmington.

Jason Clark, 44, was working on the roof of a warehouse project about 8:30 a.m. in the 30100 block of South Ridge Way in Wilmington when he fell to his death, according to Wilmington police and the Will County coroner’s office.

An autopsy Monday determined Clark, who lived in Bourbonnais, suffered multiple injuries due to a fall, the coroner’s office said. Final cause and manner of death will be determined at a later date pending police, autopsy and toxicological reports.

OSHA has opened an investigation into the worker fatality, spokesman Scott Allen said Tuesday morning. He did not provide additional details.