A Libertyville man was killed early Saturday when he fell out of a party bus on the Tri-State Tollway near Deerfield and was struck by a passing vehicle.
James J. Larsen, 27, was a passenger on the bus and had stood up to change the volume on the radio about 3 a.m., Illinois State Police Master Sgt. Jerad Klint said. He stumbled, went down the stairs, fell out the door onto the highway and was struck by the other vehicle, Klint said.
"It sounds like it was a freak accident," Klint said.
Larsen was pronounced dead at the scene.
The vehicle that struck Larsen didn't stop, and police are searching for that auto and its driver. No one on the bus saw the other vehicle hit Larsen, police said.
One of the car's bumpers was torn off by the impact, though, so police will try to learn about the vehicle from that evidence.
In an email to ABC 7 Chicago, Larsen's mother, Kimberly Larsen, said her son "was a very smart young man, doing the right thing -- not drinking and driving. He was out with his friends having a good time. We were so proud of him and so saddened that his life was cut short. He had his whole life ahead of him. We loved him so very much. He was truly the love of our family."
The accident happened on the northbound side of the Tri-State Tollway, south of Lake-Cook Road. The bus was going about 70 mph at the time.
About 30 people were aboard the 2012 Freightliner bus. Klint didn't know their destination or where they had come from.
Police don't believe anyone pushed Larsen and think he fell on his own. Investigators will try to determine if the door was locked properly or if it malfunctioned, Klint said.
"There are still a lot of questions to be answered," he said.
The party bus company, Select Limo Inc. of Chicago, has been issued a couple of citations, including for unsafe equipment, ABC 7 reported. Select Limo Inc. did not immediately return a request for comment.
Klint called the case one of the strangest he's seen in his 20-year career.
Two lanes on the northbound side of the highway were closed as police investigated Larsen's death, causing traffic delays that lasted for hours.
An autopsy could be performed Sunday, a representative for the Cook County medical examiner's office said.