Emergency personnel examine the scene after an Amtrak passenger train struck a backhoe, killing two people, in Chester, Penn., April 3, 2016. 
Photo by Dominick Reuter/Reuters

Amtrak train derailment near Philadelphia leaves 2 dead, 35 injured

Two people were killed and 35 injured Sunday morning when an Amtrak train struck a backhoe and derailed south of Philadelphia, according to authorities.

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 at about 8 a.m. according to Amtrak.

Two people, who were not passengers on the train, were killed, and at least 35 passengers suffered non-life-threatening injuries, said Chester Fire Department Commissioner Travis Thomas.

The pair who died were Amtrak employees, NBC Philadelphia reported.

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. Holmes said he saw some people bloodied, but their injuries looked “minor.”

Stephanie Burroughs, another passenger on the train, 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, North Carolina, and Philadelphia will be suspended until at least Sunday afternoon, Amtrak said.

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 of the crash, and National Transportation Safety Board investigators were en route, according to the agency.

Authorities haven’t officially yet determined the cause of that derailment but have said the train was traveling twice the speed limit. 

This article originally appeared on NBCNews.com.