The shooting happened around 4:59 p.m. in the 2800 block of South Kedzie Avenue, Chicago police said.
Officers were alerted to the shooting by gunshot detection technology, CPD said.
A 19-year-old man was found shot at the scene, police said. He was later pronounced dead at Stroger Hospital.
The two other victims, a 19-year-old woman and a 20-year-old man, took themselves to Mt. Sinai Hospital, police said. The woman had a gunshot wound to the leg and was in good condition, and the man had multiple gunshot wounds and was in critical condition.
No further information about the shooting was immediately available.
No one was in custody. Police continue to investigate.