Transcript for Amtrak Train's Black Box Recovered From Crash
Federal investigators are on the scene tonight. As you heard me report there, that train was traveling more than twice the speed limit as it hit that turn. The train's engine, less than a year old and the tracks inspected the day before. ABC's David Kerley on the crucial Klums already tonight, he's here in Philadelphia, as well. David? Reporter: Good evening, David. You mentioned it. The most important clue is speed. And this train was going faster than the speed limit on the straight part of the track and double the speed on the curve that's behind these buildings. The question tonight, why was it going so fast? This box, the event data recorder, items the horrific story of too much speed. The devastating destruction of the amtrak train cannot hide the clues that will solve this tragedy. This is about speed? Certainly the speed of the train is something that we will be looking at to determine if that was a factor in the derailment. Reporter: The rail lines north out of Philadelphia are straight, with a speed limit of 80 miles an hour. But approaching the Frankford neighborhood, a left corner. The speed is cut to 50 miles an hour. But amtrak train 188 leaves the philly station at 9:10 P.M. And 11 minutes later, at 9:21, it is traveling at twice that speed, 106 miles an hour, when the engineer trips the emergency brakes. It's too late. When it hits the corner, the train jumps the tracks, which are twisted and deformed by the force. The engineer survives, suffering only minor injuries. He talked to police briefly, but did not give a formal statement before calling a lawyer and leaving the police station. Can you think of any reason a train having just left the station would get up to 100 miles an hour? Well, we want to look at that. We want to look at the acceleration of the train. We want to look at how the train was operated. Reporter: The 1-year-old high tech electric engine came to rest upright in the dirt. But behind it, the first passengerer car, twisted and mangled. The next three cars on their side. The last three still standing. Ntsb board member sumwall tells me they are going to remove five of the cars and the engine. They are leaving two cars there, the most damaged cars. David, there is a chance there may be additional victims in the damaged cars. Of course. David Kerley, who covers transportation, right here in Philadelphia with us. We're learning more at this
This transcript has been automatically generated and may not be 100% accurate.