(CHICAGO) The Occupational Safety and Health Administration has opened an investigation after a man driving a luggage vehicle was killed in a crash Friday night at Midway International Airport on the Southwest Side.

About 11:20 p.m., 52-year-old Michael Yates was ejected from his luggage vehicle when it crashed into another luggage vehicle at Midway, police and the Cook County medical examiner’s office said.

Yates, of the 400 block of Heather Lane in Carol Stream, was taken to Advocate Christ Medical Center in Oak Lawn where he was pronounced dead, authorities said. An autopsy Saturday found Yates died of multiple injuries suffered in the crash and his death was ruled an accident.

A Chicago Department of Aviation spokeswoman said the crash involved Southwest Airlines employees and referred all questions about the incident to Southwest and Chicago Police.

“After an accident involving ground equipment, one of our ramp agents at Chicago Midway passed away last night,” Southwest spokeswoman Melissa Ford said in a statement. “Our hearts go out to his family during this difficult time. Resources are on site to support our Southwest family at Midway.”

As of Monday morning, OSHA has opened an investigation into the incident, according to spokeswoman Rhonda Burke.

The police Major Accidents Investigation Unit is also investigating the crash.