Police say a construction worker was killed and three others were injured when a 45-ton beam fell on them as they worked on a bridge in a Chicago suburb.

Des Plaines Fire Department Chief Alan Wax says one worker was taken to a hospital in critical condition early Tuesday and later pronounced dead. Three others suffered minor injuries and have been released from hospitals.

The workers were in lifts trying to remove the 180-foot-long beam under Interstate 90 when it collapsed on them around 3 a.m.

Wax says Occupational Safety and Health Administration investigators are on the scene. He says the cause wasn't immediately known.