CNN Forensic Files March 14, 2014 08:08:00
Divers recovered the train's event recorder from the bayou, which is like an airline's flight data recorder. the tape revealed the train was traveling at 72 miles per hour and there was no brake application. whatever caused the crash, the engineer never saw it. investigators also discovered the signals on the track were green. >> the signals are controlled by a current that goes through the rail, and if the rail breaks, the signal will immediately turn red. so, the signal didn't turn red. >> the bridge was originally built in three sections. the southern section was a 165-foot steel truss brid...