HOBOKEN, N.J. — The New Jersey Transit train that crashed into Hoboken Terminal last week was traveling twice the speed limit at the moment of impact, federal investigators said Thursday.

The National Transportation Safety Board, which has been investigating the fatal crash, said the train was traveling at 21 mph when it crashed through the terminal, killing a Hoboken women and injuring 108 people.

The station's speed limit is 10 mph. Information from the commuter train's data recorders revealed it was traveling at 8 mph with the throttle in the idle position less than a minute before the crash, the NTSB announced. The throttle was increased nearly 40 seconds before the crash, and the train maxed out at 21 mph before crashing.

Just prior to the collision, the throttle returned to its idle position. The train's engineer hit the emergency brake less than a second before the crash.

"The NTSB has not determined probable cause and cautions against drawing conclusions from these facts alone," the agency wrote in a statement.

The crash has already inspired a policy change at NJ Transit, which will now require a second engineer in the front car when a train pulls into Hoboken Terminal or the NJ Transit station in Atlantic City.

At most terminals, a train entering the station area above the speed limit triggers a signal alerting the engineer the train is going too fast.

In Hoboken, that system does not exist: Engineers must instead rely solely on the "dead man" brake, which requires an engineer to keep one foot on a pedal at all times. If the foot leaves the pedal, the emergency brakes engage.