The shooting reportedly took place both inside and outside an apartment in the 2200-block of West Maypole Street. Witnesses said the suspect fled on foot through a nearby park.
Chicago fire officials said two victims were taken to Stroger Hospital in critical condition. Another victim was taken in serious condition to Stroger, and the fourth victim was taken to Mt. Sinai Hospital in serious condition.
No information about the victims beyond their conditions have been released.
Police have not released any details about the circumstances of the shooting, nor any information about the suspect. An investigation is ongoing.