A 4-year-old boy was killed in a car crash along the Dan Ryan expressway.
An SUV was heading northbound near 87th Street when it struck a side wall Sunday.
A back window shattered, and the boy was thrown from the vehicle.
The child was in a booster seat, other children inside the SUV were wearing seatbelts.
The driver is believed to be the boy`s father.
He was found a short distance away on the 83rd Street ramp.
He is being questioned by police.