As an Amtrak train carrying 139 passengers approached Cayce, South Carolina, a switch would lead that train directly into a parked cargo train.
2 Amtrak employees died during that head-on crash Sunday morning in Lexington County, 116 were injured.
An NTSB investigation revealed that a switch on the tracks that led the train down the wrong track was in working condition. The investigation also revealed that signals at the track were also not working, as they were under maintenance for a safety system upgrade for Positive Train Control.
Positive Train Control or PTC as it's commonly known is a remote braking system for passenger trains. A Congressional mandate required all passenger trains to have the PTC upgrade in 2015, that deadline was extended to the end of 2018.
The NTSB stated that the PTC system could have prevented this crash.
Tom Howie is a former CSX employee and is now a current railroad safety consultant for railways. Howie helps makes sure that railways are following regulations and codes.
Howie states that PTC dominates discussions in the industry, as the deadline approaches to have the systems installed. Installing the remote braking system isn't as simple as it would seem, as the technology for PTC is sometimes too advanced for the matching rail technology.
The investigation into the deadly crash will continue throughout the week, according to the NTSB.