The shooting took place at about 11:43 p.m. in the 7200-block of South Avers Avenue.
Police said a group of five people was walking when three people in the group pulled out guns and fired shots at the other two.
The 18-year-old was shot in the head and transported to Advocate Christ Hospital, where he was pronounced dead, police said.
The 15-year-old suffered a graze wound to the cheek and was transported to Advocate Christ Hospital in good condition.
The three suspects fled the scene but were taken into custody by responding officers, police said.
Police said two guns were recovered from the scene. Area One detectives are investigating and charges are pending.
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