Photos: Deadly train derailment in Philadelphia

Emergency personnel work at the scene of a deadly train derailment in Philadelphia.

Injured passengers that were bused from to New York from Philadelphia wait at Penn Station in New York. Rescuers on Wednesday combed through the mangled wreckage of a derailed train in Philadelphia after an accident that left at least six dead, as the difficult search for possible survivors continued.

Investigators and first responders work near the wreckage of an Amtrak passenger train carrying more than 200 passengers from Washington to New York that derailed in north Philadelphia.

Investigators and first responders work near the wreckage of an Amtrak passenger train that derailed in north Philadelphia.

Rescuers combed through the mangled wreckage of a derailed train in Philadelphia after an accident that left at least six dead, as the difficult search for possible survivors continued.

A man looks at an Amtrak train that derailed on its way from Washington to New York City in Philadelphia.

Passengers injured in an Amtrak train derailment who were bused from to New York from Philadelphia walk through Penn Station in New York.

Emergency personnel work to help victims in a deadly train wreck May 12 in Philadelphia.

A passenger is carried away after the derailment. Northeast Regional Train 188 was traveling from Washington to New York City.

Emergency personnel at the scene of a derailed Amtrack train headed to New York City.

Train passengers gather near the derailment site.

A passenger gets medical assistance after an Amtrak train derailed in Philadelphia en route to New York City.