NTSB investigating fatal Amtrak derailment near Philadelphia

Federal investigators were on the scene this morning of an Amtrak Northeast regional train derailment north of Philadelphia that occurred Tuesday night. The incident left six people dead and more than 140 injured.

The National Transportation Safety Board (NTSB) launched a go-team to the site and was expected to announce additional details about the accident later this morning. The cause is not yet known.

The U.S. Department of Transportation will assist the NTSB in the investigation, U.S. Transportation Secretary Anthony Foxx said in a prepared statement issued this morning.

Today, modified Amtrak service will be provided between Washington, D.C., and Philadelphia, Harrisburg, Pa., and Philadelphia, and New York City and Boston. Amtrak trains will not be running between New York and Philadelphia, but New Jersey Transit will honor Amtrak tickets between New York City and Trenton, N.J., Amtrak announced.

About 238 passengers and five crew members were on board Amtrak Train 188 when it derailed on a curve around 9:30 p.m. Tuesday. At a press conference later in the evening, Philadelphia Mayor Michael Netter described the scene as "an absolute disastrous mess."

The train had left Union Station in Washington, D.C., at about 7:30 p.m. and was on its way to New York City when the incident occurred.

Former U.S. Rep. Patrick Murphy was riding in the train's cafe car when the crash occurred, and tweeted several photos from the scene. A military veteran, Murphy assisted the injured and helped several people get out of the train car, one of several to roll off the track.