CHICAGO (CBS) —A man was shot on the southbound Red Line Train platform near Garfield Park Monday afternoon, halting trains for at least an hour.

Before the shooting, the 23-year-old man who was shot was involved in an altercation at the turnstile leading to the platform, according to a witness. As he waited for a train around 2 p.m., a man pulled out a gun, shooting him in the shoulder and chest, police said.

The man who was shot was taken to the University of Chicago trauma center, where his condition was stabilized. No one else was hurt.

The CTA advised Red Line riders to use the Green Line or #29 State buses while southbound Red Line trains were stopped. The Garfield Park Station runs south along the Dan Ryan Expressway.

Police said the man who was shot is a documented gang member.