Railway signaling system was down during crash

CAYCE, S.C. — Federal authorities said Monday that a railway signaling system in South Carolina was down for maintenance when an Amtrak train was mistakenly sent off a main track and down a side spur — and into a parked freight train. The ensuing crash early Sunday killed an Amtrak engineer and conductor and injured more than 100 passengers.

National Transportation Safety Board chairman Robert Sumwalt said Monday that the system was down so crews could install a “positive train control” system, which uses sensors and GPS to prevent trains from colliding or derailing. The system knows the location of all trains and the positions of all switches to prevent the kind of human error that can put two trains on the same track.

Mr. Sumwalt had said earlier that if the system were up and running, it likely would have prevented the Amtrak train from colliding head-on into the freight train near Cayce.

Authorities said 116 of the other 147 passengers and crew on board the train were taken to hospitals, mostly with minor injuries.

Mr. Sumwalt said data recovered from the Amtrak train show the engineer hit the emergency brakes three seconds before the trains collided at 50 mph.

Federal investigators have been trying to figure out why a switch was in the wrong position.

Mr. Sumwalt said the passenger train hurtled down a side track near Cayce around 2:45 a.m. Sunday after a stop 10 miles north in Columbia because a switch had been locked in place, diverting it from the main line. A crew on the freight train had moved the switch to drive it from one side track — where it unloaded 34 train cars of automobiles — to the side track where it was parked.

The switch was padlocked as it was supposed to be, Mr. Sumwalt said.