Multiple ambulances responded to a traffic accident on the Kennedy Expressway about 500 North.
A van, from a church in Milwaukee, crashed on the expressway.
At least 12 people were injured and taken to area hospitals.
The Emergency Medical Services Plan 2 called Saturday night sent at least 10 ambulances to the response scene on the outbound Kennedy near Ohio Street.
State Police said one person was in serious to critical condition but none of the injuries appeared to be life threatening.
All outbound lanes were blocked at Hubbard’s Cave leading to snarled traffic on the Kennedy in the Loop area.