Five people are confirmed dead after a northbound Amtrak passenger train heading from Washington, D.C. to New York City derailed near Philadelphia late Tuesday. Six were critically wounded, and at least 50 additional passengers sustained injuries. Philadelphia Mayor Michael Nutter called the incident "an absolute disastrous mess," adding, "I have never seen anything like it in my life."
"We do not know what happened here," Nutter said just before midnight. Nutter said that the train's engine had completely separated from the train, and that one car was perpendicular to the others.
An estimated 238 passengers and five crew members were on board when approximately 8-10 cars derailed. The National Transportation Safety Board dispatched a team of investigators to the site. Police officials described the incident as a level-3, mass-casualty event.
"Our hearts and prayers go out to the victims and injured in this accident. We are assembling on site and will begin a thorough investigation into the cause of this accident," Acting Federal Railroad Administrator Sarah Feinberg said.
Firefighters at the scene described it as devastating, saying the cars came completely off the rails and their outer shells were completely destroyed. Some passengers were only rescued when firefighters brought in hydraulic tools to help lift them to safety.
Passengers who were thrown across the train cars kicked out windows and forced open doors to escape Amtrak 188, which went off the rails at approximately 9:30 p.m. ET. Men and women traveling from Washington to New York helped one another stumble out into a dark and wooded area northeast of Philadelphia, bloodied and bruised. First responders who arrived on the scene began sorting passengers by their injuries and searching cars for additional casualties. Many passengers were taken by bus and ambulance to area hospitals.
WATCH: Eyewitness describes fatal derailment
Ambulance drivers notified nearby hospitals by radio of passengers with injuries including lacerations, neck injuries, and limb injuries, including fractures to the lower and upper extremities.
Former U.S. Rep. Patrick Murphy, who was on board the train, estimated the train was traveling at approximately 60-70 miles per hour when "all of a sudden, it went off the rails. ... We flipped over ... The next thing I know, I was on the other side of the car, upside down," Murphy told MSNBC's Lawrence O'Donnell. Amtrak passenger trains do not have seat belts.
"NBC Nightly News" producer Janelle Richards was also on the train and told MSNBC's Rachel Maddow she heard a loud crash and saw passengers fly into the air. Richards also reported seeing "a lot of smoke." Richards said she saw injured passengers who were bleeding. "It seemed like -- even if people were shocked -- they were not badly injured," Richards said.
Approximately an hour after the train derailed, passengers were still being rescued from the scene.
Northeast Corridor service between New York and Philadelphia is suspended until further notice. According to Amtrak, its Northeast Corridor "is the busiest railroad in North America, with more than 2,200 trains operating over some portion of the Washington-Boston route each day." The route is located near I-95 and the Delaware River, which divides Pennsylvania from New Jersey.
The train was scheduled to arrive in New York City at 10:30 p.m.
Those trying to contact passengers should call the Amtrak hotline at 1-800-523-9101.