Authorities say the victim was moving between cars and ended up on the track on the Orange Line near the 2500-block of South Archer. It is not known how the victim ended up on the tracks.
The train involved remains in place between Canal and Halsted.
Power remains shut off to the track. Orange Line trains to and from Midway Airport are not running and Archer Avenue is closed.
The CTA advised customers to use shuttle buses at Roosevelt or the 62 Archer bus on State to get to 35th and Archer for service toward Midway.
The CTA says it was able to move passengers to the last two cars on the train and that they were able to exit through the Halsted station.