Man dies after tumbling from van on Dan Ryan

A man died after tumbling from the van his father was driving late this afternoon on the Dan Ryan expressway.
 Timothy Kreiss, 55, was found in the express lanes near 45th Street about 4:30 p.m. and taken to Northwestern Memorial Hospital, according to Illinois State Police and the Cook County medical examiner’s office.
 Kreiss, of Oak Park, was pronounced dead at 4:57 p.m. at the hospital.
 It’s unclear why the man left the vehicle, but State Police Trooper James Gawel said no other vehicles were involved.
 Police didn’t know how fast the van was traveling when the man exited.
 Kreiss’ father was driving and he was the only other person in the vehicle