Two crewmembers died and 116 passengers and crew were injured in a tragic train accident in South Carolina on Sunday, Feb. 4. An Amtrak train ended up on the wrong track and crashed head-on into a parked CSX freight train.

The precise chain of events is under investigation. But an official from the National Transportation Safety Board said that available technology could have prevented this. “Positive train control” can spot problems ahead and slow or stop trains.

What went wrong?

According to officials at the scene, a switch had been manually changed and padlocked in place, diverting the moving passenger train to a side track where the freight train was parked. Upon colliding, the Amtrak train derailed and several cars turned over.

The Amtrak was traveling within the speed limit of 59 miles per hour and probably had no time to pull the brakes. A National Transportation Safety Board (NTSB) official said there was “no way” that the conductor could have stopped the train in time to avoid the collision.

Who is to blame?

CSX owns the tracks in Cayce, where the accident occurred, and the company is responsible for making certain that trains travel on the correct tracks. It is not yet known why the track was lined-up incorrectly.

The NTSB has been pushing for a “positive train control” safety system for decades. The PTC system detects problems on the tracks ahead of trains and automatically slows them down.

Congress required many railroad track companies to adopt the safety system by the end of 2015. However, that deadline was extended to the end of this year. If it had been in place, this disaster may have been avoided and lives saved.

It will likely take up to a year or more for investigators to determine who is to blame .

Numerous deadly train accidents

This is the third deadly Amtrak crash in less than two months’ time. Three people died in a derailment in the state of Washington in the middle of December, and another died in a truck-train collision in West Virginia on the last day of January.

Positive train control would have likely averted the Washington crash, in which an Amtrak train on its maiden passenger run took a curve much too fast and plunged onto a highway. The Amtrak train in West Virginia was carrying several members of Congress, some of whom suffered minor injuries. The cause is not known, though the investigation has focused on the driver of the garbage truck.