Des Plaines — Federal officials are investigating two companies after a construction worker was killed and three others were injured in suburban Chicago.

The accident happened about 3 a.m. Tuesday when a 40-ton a steel bridge beam fell on the workers as they tried to remove it at Interstate 90. Occupational Safety and Health Administration officials say the beam rolled from a pier support while workers cut steel bracing it.

OSHA officials say it has opened an investigation into the deceased worker’s employer, Omega Demolition Corp. of Elgin, and the general contractor, Judlau Contracting Inc. of New York. Neither company immediately responded to calls and emails seeking comment.

Des Plaines fire officials say three workers were treated and released from hospitals. The fourth was pronounced dead at a hospital.