CAYCE, S.C. >> An Amtrak passenger train slammed into a parked freight train in the early-morning darkness today after a thrown switch sent it hurtling down a side track, authorities said. Two Amtrak crew members were killed, and more than 100 people were injured.

It was the third deadly wreck involving Amtrak in less than two months.

The Silver Star, en route from New York to Miami with nearly 150 people aboard, was going an estimated 59 mph when it struck the empty CSX train around 2:45 a.m., Gov. Henry McMaster said.

The crash happened near a switchyard about 10 miles (16 kilometers) south of Columbia where railcars hauling automobiles are loaded and unloaded.

Many of the passengers were asleep when the crash jolted them awake and forced them into the cold.

“I thought that I was dead,” said passenger Eric Larkin, of Pamlico County, North Carolina, who was dazed and limping after banging his knee.

Larkin said he was on his way to Florida when he was awoken by the crash. The train was shaking and jumping, and his seat broke loose, slamming him into the row in front of him, he said. He heard screams and crying all around him as he tried to get out. Other passengers were bleeding.

Robert Sumwalt, chairman of the National Transportation Safety Board, said investigators found a track switch had been set in a position that forced the Amtrak train off the main track and onto the siding.

He said the question for investigators is why that happened.

Amtrak President Richard Anderson pointed the finger at CSX, saying the signal system along that stretch is run by the freight railroad but was down at the time of the wreck, forcing CSX dispatchers to route trains manually. The NTSB said it was working to confirm that.

CSX issued a statement expressing condolences but said nothing about the cause of the accident.

Sumwalt said that positive train control — a GPS-based safety system that can automatically slow or stop trains — could have prevented the accident.

“That’s what it’s designed to do,” he said, referring to technology that regulators have been pressing for for decades with mixed success.

The conductor and engineer aboard the Amtrak locomotive were killed. And 116 people were taken to four hospitals, according to the governor.

At least three patients were hospitalized in critical or serious condition, with nearly all the rest treated for minor injuries such as cuts, bruises and whiplash, authorities said.

Palmetto Health emergency room doctor Eric Brown said so many passengers were hurt that they were brought in on two buses, and a tent that had been set up as a waiting room to keep people separate from flu patients was turned into a triage area.

The locomotives of both trains were left crumpled, the Amtrak engine on its side. One car in the middle of the Amtrak train was snapped in half, forming a V off to one side of the tracks.

“It’s a horrible thing to see, to understand the force involved,” the governor said after touring the scene.

Investigators recovered a camera from the front of the Amtrak train and were looking for the data recorders from the two trains.

The switch that triggered the crash was found padlocked in position, which conductors are supposed to do when they move a train from one line to another, Sumwalt said.

Amtrak officials gathered up luggage and other belongings and within hours put passengers aboard buses to their destinations.

Before being sent on their way, those who were not hurt were taken to a shelter set up at a middle school, and local businesses provided coffee and breakfast.

The dead were identified as engineer Michael Kempf, 54, of Savannah, Georgia, and conductor Michael Cella, 36, of Orange Park, Florida.

“Any time you have anything that happens like that, you expect more fatalities. But God blessed us, and we only had the two,” Lexington County Coroner Margaret Fisher said, her voice choked with emotion.

On Wednesday, a chartered Amtrak train carrying Republican members of Congress to a retreat slammed into a garbage truck in rural Virginia, killing one person in the truck and injuring six others.

And on Dec. 18, an Amtrak train ran off the rails along a curve during its inaugural run near Tacoma, Washington, killing three people and injuring dozens. It was going nearly 80 mph, more than twice the speed limit.

With the recent string of crashes, “it’s becoming almost like an epidemic for Amtrak,” said Najmedin Meshkati, a University of Southern California engineering professor who has studied positive train control.

Positive train control is in place in the Northeast, but railroads that operate tracks used by Amtrak elsewhere in the U.S. have won repeated extensions from the government. The deadline for installing such equipment is now the end of 2018.

After the latest crash, Democratic Sen. Richard Blumenthal of Connecticut said the nation’s railroads must be made safer, declaring, “Business as usual must end.” He said proven technology such as positive train control cannot continue to be delayed.

The worst rail tragedy in recent South Carolina history took place in 2005 when a freight engineer parked a train on a side track near a textile mill in Graniteville and forgot to flip the switch back to keep trains on the main track.

A freight train passing through went barreling down the side track and slammed into the parked train, killing nine people, most of them millworkers choked by chorine gas that leaked from a damaged tanker car.

With the recent string of crashes, “it’s becoming almost like an epidemic for Amtrak,” said Najmedin Meshkati, a University of Southern California engineering professor who has studied positive train control.