The shooting happened on the Near West Side near North Wolcott and West Maypole avenues just before 7 p.m., police said.
ABC7 spoke with Thomas Kendall, the brother of one of the victims critically injured.
Kendall said his brother, who is 18 years old, was out with his of friends, heading to the Lil Durk concert at the United Center, when a group of people on bikes approached them.
The group then tried to mug the 18-year-old and his friends, Kendall said. A struggle ensued, and that's when a suspect fired shots.
Kendall's brother, shot in his chest, was listed in critical condition.
Another man, 19, was shot in his rib area and listed in critical condition.
A 15-year-old boy, shot in his hand and grazed in his abdomen, was listed in good condition.
All three victims are being treated at Stroger Hospital, and their families said they are undergoing surgery.
At one point, ABC7 cameras were rolling as police officers ran blocks away, but investigators say no one is in custody.
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