CHICAGO (CBS) — Four men were wounded in a shooting outside of a gas station in the 3900 block of West Roosevelt.

According to Chicago police, the men were standing outside when an unknown man exited a vehicle and fired shots, striking all four men.

Three of the men — ages 35, 19, and 20 — were transported by the Chicago Fire Department to Stroger Hospital. The fourth man, a 21-year-old, self-transported to Mount Sinai.

The 35-year-old man is in critical condition, suffering gunshot wounds to his lower backside, hip and leg. The other three men are in stable to good condition, suffering wounds to the arms, legs, and face.

The offender fled the scene and is not in custody.

Area North detectives are investigating.