On March 24, 2014, a Chicago Transit Authority (CTA) passenger train overran the bumper at O'Hare station, injuring 34 people.

At 2:50 a.m. local time (07:50 UTC) on March 24, 2014, a passenger train overran the bumper at O'Hare . The front car of the eight-car train partially ascended an escalator.^[1] While a spokesman initially stated that it was likely that the train entered the station at too high a speed,^[2] later estimates indicated that the train entered the station at 25 to 26 miles per hour (40 to 42 km/h), which was not an excessive speed.^[3] At least 50 firefighters and paramedics responded to the accident.^[4] Thirty-four people were injured.^[5] They were taken to the Advocate Lutheran General Hospital, the Our Lady of the Resurrection Medical Center, the Resurrection Hospital and the Swedish Covenant Hospital.^[1]

Following the accident, the line between O'Hare and Rosemont was closed, with a replacement bus service in place. A CTA spokesman initially stated that the line could be closed for as long as 48 hours while recovery of the train was undertaken.^[1] This was later revised upwards to a week.^[3] The front two cars of the train were damaged in the accident.^[1] Damage was estimated at $6,000,000. On March 26, work began to scrap the lead car on site.^[6] The derailed train was removed from the station on March 27.^[7] The station reopened on March 30, 2014, at 2:00 p.m. The escalator damaged in the crash was replaced by stairs.^[8] Damage amounted to $11,196,796.^[5]

Photographs show that the train involved in the accident was made up of four two-car 2600-series trainsets, with 3061/3062 as the leading pair.^[9][10]

The National Transportation Safety Board (NTSB) opened an investigation into the accident.^[11] Investigators focused on the theory that the motorwoman, 25-year-old Brittney Tysheka Haywood,^[12] fell asleep at the controls.^[1] She stated that she had recently performed "a lot of overtime".^[13] When interviewed by the NTSB, she admitted falling asleep at the controls and disclosed that she had done a similar thing the previous month, which resulted in an overshoot at Belmont (Blue) on February 1. She did not reveal to CTA that she had fallen asleep when questioned about the overshoot.^[14][15] The investigation was hampered by the train's lack of a train event recorder, although it was fitted with a video camera. The recording from the camera was examined.^[1] Images from 41 cameras within the station were also studied.^[3] The NTSB's report ultimately confirmed the original findings.^[16][17]

As a direct consequence of the accident, the CTA reduced the speed limit into the O'Hare station from 25 miles per hour (40 km/h) to 15 miles per hour (24 km/h). The area of the speed limit was also extended away from the station.^[15] The train operator was fired.^[18]