Two people were killed and 35 others were injured Sunday morning when an Amtrak train struck a backhoe and derailed south of Philadelphia, authorities said.
Seven crew members and 341 passengers were on the train traveling from New York to Savannah, Georgia, when the lead engine disconnected from the tracks in Chester about 8 a.m., according to Amtrak.
Two people, who weren't passengers on the train, were killed, and at least 35 passengers suffered non-life-threatening injuries, Chester Fire Commissioner Travis Thomas said.
Sen. Chuck Schumer, D-New York, said at a news conference that he was told by Amtrak that the workers who were killed were the backhoe's operator and a supervisor, both of whom worked for Amtrak.
Passengers said the collision between the train and the backhoe, followed by the derailment, caused a fireball and a plume of smoke.
"There was an explosion, then a fire, then the windows busted out," said Linton Holmes, a 15-year-old from Wilson, North Carolina, who was riding in the back of the train. Linton said he saw some people bloodied, but their injuries looked "minor."
Stephanie Burroughs, another passenger, told NBC News that those around her were relieved the cars didn't flip over. "We immediately thought this is a train derailment. But then we stayed upright," Burroughs said.
Northeast Corridor service between Wilmington, Delaware, and Philadelphia was expected to be back to normal Monday, Amtrak said. Limited service between the two cities resumed at about 2:30 p.m. Sunday, according to Amtrak.
It wasn't immediately clear what the backhoe was doing on the tracks. Officials with the Federal Railroad Administration said they had arrived on the scene, and National Transportation Safety Board investigators were en route, according to the agency.
The derailment comes nearly a year after eight people were killed and more than 200 others were injured when an Amtrak train traveling from Washington, D.C., bound for New York City derailed in Philadelphia.
Authorities haven't officially determined the cause of that derailment but have said the train was traveling twice the speed limit.