Chicago police said a train hit a 51-year-old man in the 100-block of North State Street just before 2:50 p.m. He was taken to Northwestern Memorial Hospital in critical condition.
The train operator was also taken to Northwestern in fair condition for observation, police said.
No passengers reported any injuries.
Trains were standing at Washington in the Loop just before 3 p.m., the CTA said.
Red Line trains were rerouted to the elevated lines between Fullerton and Cermak-Chinatown, the CTA said just after 3 p.m.
SEE MORE: Latest traffic in Chicago
The CTA said later Tuesday afternoon that trains were running normally, with delays.
Area Three detectives are investigating.
If you are experiencing suicidal, substance use or other mental health crises please call or text the new three digit code at 988. You will reach a trained crisis counselor for free, 24 hours a day, seven days a week. You can also go to 988lifeline.org or dial the current toll free number 800-273-8255 [TALK].