Police said the occupants of a Chrysler Town and Country minivan were exchanging gunfire with another vehicle, possibly a black SUV, while traveling in the 1100-block of North Lake Shore Drive at about 10:50 p.m.
The minivan then rear-ended a Fiat and a Toyota Corolla before hitting a concrete median.
Police said three to four people inside the minivan fled the scene on foot and have not been located.
Two women driving the Fiat and Corolla were not injured.
No one is in custody. Area Three detectives are investigating.