NEW YORK (AP) — Philadelphia Mayor Michael Nutter says at least five people have been killed in the an Amtrak train derailment.

Emergency personnel help a passenger at the scene of a train wreck, Tuesday, May 12, 2015, in Philadelphia. An Amtrak train headed to New York City derailed and crashed in Philadelphia. (AP Photo/Joseph Kaczmarek)
Emergency personnel help a passenger at the scene of a train wreck, Tuesday, May 12, 2015, in Philadelphia. An Amtrak train headed to New York City derailed and crashed in Philadelphia. (AP Photo/Joseph Kaczmarek)

A fire officials says at least six people were critically injured. The train, with 243 people aboard, was headed to New York City from Washington D.C. It detailed in Philadelphia’s Port Richmond neighborhood, near the Delaware River.

Nutter called it “an absolute disastrous mess” and said he’d never seen anything like it.”

The cause of the crash isn’t immediately known. The National Transportation Safety Board said it was gathering information about the derailment.