Updated 04/28/15 – 5:07 p.m.
CHICAGO (CBS) — The National Transportation Board has blamed last year’s Blue Line derailment at O’Hare International Airport on operator fatigue and design flaws with the terminal’s automated braking system.READ MORE: Chicago Weather: Cooler Trend Next Week After Quiet Weekend
“The layers of protection that were designed to prevent such an accident failed,” NTSB Chairman Christopher Hart said at a hearing Tuesday morning in Washington.
Hart pointed to the trip arms and bumping posts at the O’Hare terminal at the end of the tracks, saying neither could adequately slow or stop the train, after the operator nodded off while pulling into the terminal. The train was going approximately 26 mph as it pulled into the station on the center track.
When the operator failed to hit the brakes as the train pulled in to the O’Hare terminal, and the automated braking system could not stop the train, it jumped the tracks, and smashed into an escalator.
“Fortunately, nobody was on the escalator at the time of the accident, which occurred at about 2:49 in the morning. If this accident had occurred a few hours later, during rush hour, it could have had far more tragic results,” Hart said.