An Orange Line train derailed early Friday in the Chicago Transit Authority train yard near Midway Airport.
No passengers were aboard the train, but two CTA workers were injured, according to the agency.
The train jumped the rails just before 2:30 a.m. Video of the incident showed one train off the tracks and partially leaning onto another train.
The extent of the workers' injuries isn't known, but they were seen transported on stretchers to MacNeal Hospital in Berwyn.
The derailment did not affect the morning commute.