The National Transportation Safety Board said it’s trying to determine why a switch was locked in a position that sent an Amtrak train off the main line to a side track where it rammed a parked CSX freight train early Sunday, killing two and injuring more than 100.
NTSB Chairman Robert Sumwalt said a key to figuring out what caused the deadly crash is determining why the Silver Star was diverted to another line by a padlocked switch — a common practice known as “lined and locked.”
The switch was left in the wrong position after CSX crews moved their 36-car train across four sets of tracks as it unloaded automobiles, Sumwalt said.
As the freight train traveled over the main track the switch was activated to allow it to move to the side track. It wasn’t moved back.
“Of course, key to his investigation is learning why that switch was lined that way, because the expectation of course is that the Amtrak would be cleared and operating straight down,” he said during a briefing Sunday afternoon.
Investigators found the switch still padlocked Sunday morning, Sumwalt said.
He also said that NTSB investigators didn’t know if signals further up the line indicated the track had been switched.
Instead of staying on the main line, the Silver Star en route to Miami from New York City slammed into the rear of the stationary CSX train while going the speed limit of 59 mph.
The Amtrak train was carrying 139 passengers and eight crew members when the crash occurred at 2:35 a.m. in Cayce, S.C.
The conductor and engineer were killed in the crash.
South Carolina Gov. Henry McMaster said 116 people were taken to several hospitals in the region for treatment.
The rail line in that area is maintained and operated by CSX and Amtrak uses it through a “hosting” agreement with the freight railroad.
Amtrak’s CEO Richard Anderson earlier Sunday said the signal system was down and CSX dispatchers were manually routing trains.
”The only way the Amtrak train could have gotten onto the siding was for a switch to have been thrown,” Anderson said.
Sumwalt said while investigators so far have not found the black boxes that record data for the two trains, but have recovered the forward-facing camera mounted on the Silver Star.
That camera has been shipped to the NTSB in Washington, DC, and is being examined, he said.