An Amtrak train going from Washington DC to New York City derailed in Philadelphia late on Tuesday claiming at least five lives and injuring dozens.
Six people were critically injured and taken to nearby hospitals, Philadelphia Mayor Michael Nutter said.
At least 50 people were injured in the incident, NBC reported citing local officials.
There were 238 passengers and five Amtrak employees on board the Northeast Regional 188 train when seven cars of it derailed.
Witnesses say the derailment happened when the train was going into a turn and that front part of the train went off rails.
Amtrak said it is investigating the crash but the reason was not known immediately.
Police were trying to move people away from the train.
The Federal Railroad Administration said it is sending a team to the crash site.
Amtrak said train services between Philadelphia and New York City was cancelled.
Six people were killed and a dozen injured when a Metro North commuter train hit a car on the rails in north of New York City in February.