A 30-year-old man was in custody after his gun went off during a brawl on a CTA Red Line train Sunday night near the Sox-35th Street station on the South Side.
A 42-year-old man was sitting in a train car around 9:40 p.m. when he began arguing with someone on the train, Chicago police said.
The argument turned physical and the 42-year-old was hit in the head with a firearm, causing it to discharge, officials said.
No one was shot and the gun was recovered at the scene, authorities said.
A CTA representative said they received reports of a disturbance aboard a Red Line train at 35th and that service was temporarily delayed.
The gunman, a 30-year-old man, was taken into custody and charges were pending, police said.