Chicago police said the crash happened in the West Pullman neighborhood's 1200-block West 115th Street around 5:30 p.m.
A tow truck heading westbound on 115th Street hit a Chevy, which was traveling in the same direction, police said. The tow truck also ran into a CTA bus, which struck a parked Toyota.
The Chicago Fire Department said two children were hospitalized in serious to critical conditions. Three other people were hospitalized in good condition.
Authorities did not immediately provide further information about the crash.