The shooting happened near Milwaukee Avenue and Kinzie Street in the Fulton River District neighborhood at about 2:02 a.m.
An 18-year-old man said he was in a car when he heard shots fired and felt pain.
Chicago police said he was shot multiple times. He was rushed to the hospital in critical condition.
A second victim, 17, showed up at a hospital with a gunshot wound to the leg.
He said he was walking out of a music studio when four offenders approached, two of them armed, and they started to shoot at him.
The 17-year-old victim is expected to be okay.
There is no one in custody. CPD Area Three Detectives are investigating.
INTERACTIVE SAFETY TRACKER Track crime and safety in your neighborhood