Police are looking for a gunman who opened fire aboard a Red Line train early Wednesday, critically injuring a 29-year-old man in the Loop.
The victim and another passenger began arguing and then fighting on a southbound train in the 1100 block of South State Street, police said.
The man the victim was fighting with then shot the 29-year-old in the thigh and buttocks, police said. He was taken to Stroger Hospital in critical condition.
The shooter was not arrested and fled the train at the Roosevelt station.
The shooting disrupted Red Line service, which was running normally again as of 7:30 a.m., according to the CTA.
Area 3 detectives are investigating.
