By Roseanne Tellez

CHICAGO (CBS) — One worker was killed and a second was injured in a construction accident Tuesday morning in north suburban Evanston.

Investigators with the Occupational Safety and Health Administration are now investigating what might have gone wrong.

Police and fire officials said, around 8:25 a.m., a load of steel beams fell on two workers, apparently while a crane operating by Area Erectors Inc. was lifting the beams at a construction site for a 9-story apartment building on the 800 block of Emerson Street.

A 55-year-old man was immediately taken to NorthShore University Evanston Hospital in critical condition. He later was pronounced dead.

A second worker, a 28-year-old man, had his leg pinned under the steel, and “it took a little longer to extricate him,” according to Evanston Police spokesman Perry Polinski. That man was taken to Evanston Hospital in serious but stable condition.

On Tuesday afternoon, twisted metal still hung from the crane. Regina Henry said she “heard a bang I looked out of the window on the seventh floor right in front of the truck.”

Henry says she saw two workers down

“They were not moving so I definitely knew that there was a problem.”

It was not immediately clear what caused the steel to fall, but the crane operator was still in the cab as of 11 a.m., and firefighters appeared to be working to bring him down safely.

Area Erectors was involved in another fatal accident in January, 2015 during which a life operator was pinned between the frame on the basket and a joist, according to OSHA records.

The company also was fined for several OSHA safety violations during Wrigley Field construction work in 2016.