An Amtrak train that derailed in Philadelphia, killing seven people, was barreling into a curved stretch of track at 100 miles per hour, over twice the speed limit, when the engineer slammed on the brakes, U.S. investigators said on Wednesday.
While the cause of Tuesday night's crash that injured more than 200 people remains to be determined, experts from the National Transportation Safety Board (NTSB) believe the derailment would have been prevented by installation of an advanced safety system called "positive train control," NTSB board member Robert Sumwalt said.
The engineer of the New York City-bound passenger train fully applied the locomotive's emergency braking system as it entered the left-hand curve in the rail line, where the maximum allowed speed is 50 miles per hour (80 km per hour), Sumwalt told a news conference hours after the NTSB began its probe.