CAYCE, S.C. (NBC News) — Investigators are trying to determine what caused a deadly South Carolina Amtrak crash that killed two crew members and injured more than 100 people early Sunday morning.
The accident happened when the passenger train carrying 147 people en route from New York to Miami, was diverted from the main line.
It went onto a side track where it collided with a parked CSX freight train.
Investigators with the National Transportation Safety Board say they located and successfully downloaded an event recorder that revealed the final seconds before the crash occurred.
The Amtrak train event recorder found that seven seconds before the crash, the train’s horn was activated as it traveled 56 mph down the track.
Five seconds before the crash, the train’s brakes were applied.
Three seconds before the crash, the train’s emergency brakes were applied.
NTSB Chairman Robert Sumwalt said the Amtrak train was not speeding before it hit the parked CSX freight train head-on. But the collision was so powerful, it pushed the CSX train back 15 feet.
Sumwalt said, ironically, that indications were that the system designed to help stop trains before a collision was being prepared to be installed on the track.
The system is known as “positive train control” which uses sensors and GPS to detect the locations of trains and the position of switches.
Investigators on the scene are focusing on why a manual switch was locked in the wrong position, diverting the train.
“The expectation for the Amtrak crew is that it would be cleared all the way down through here,” said Sumwalt. “So we want to find out why this switch was in this position.”
Investigators on Monday interviewed the CSX engineer, conductor, train dispatcher and train master. They expect to interview the surviving Amtrak crew on Tuesday.
Six passengers remain hospitalized — two of them in critical condition.