Updated 03/25/14 – 4:21 p.m.
CHICAGO (CBS) — Federal investigators said an automated braking system known as a “track trip” activated just before a CTA Blue Line train derailed at O’Hare International Airport and plowed into an escalator, but it’s not clear if the system applied the brakes as quickly as it should.
NTSB investigator in charge Ted Turpin said a six-member team still has lots of evidence to gather before determining the cause of the derailment. Tuesday afternoon, they will interview the operator who was at the train’s controls.
Turpin would not speculate how soon the damaged train could be removed, and the O’Hare station could reopen.
He said a “track trip” system at the O’Hare terminal did activate as the train was pulling into the station around 2:50 a.m. Monday, and brakes were applied, but investigators aren’t sure yet if that system kicked in exactly when it should.
“Whether it did it in time or not — that’s an analysis we have to figure out,” Turpin said.