NTSB issues preliminary report on CTA derailment at O'Hare

A National Transportation Safety Board (NTSB) preliminary report on last month's Chicago Transit Authority (CTA) train accident at O'Hare International Airport found that the train derailed after the operator dozed off. The train's speed, combined with the distance to a bumper post, prevented the train's emergency braking system from stopping the train in time, according to the report, which is posted on the board's website.

The accident, which occurred at 2:49 a.m. on March 24, injured the train operator and 32 passengers. The Blue Line train derailed and hit the escalator after colliding with an end-of-track bumper post at the O'Hare station. Seconds before the derailment, the train was traveling about 26 mph as it crossed a fixed trip stop that activated the emergency braking system. Due to the train's speed, the distance from the trip stop to the bumper post was too short to stop the vehicle, the report stated.

The train operator told investigators that she had fallen asleep as the train entered the station. The last signal she recalled seeing was a yellow-over-red signal aspect, which indicated the next signal would require her to stop the train. She awoke as the train crossed the fixed stop, which was just beyond the stop signal.

The operator claimed she had worked nearly 60 hours over the previous seven days, was working her third consecutive night shift and had inadequate sleep on the Saturday before the Monday accident, the report stated.

The incident caused an estimated $9.1 million in damage to the equipment and station. The NTSB is continuing its investigation, along with the Federal Transit Administration, the Regional Transit Authority and the CTA.