At a briefing early Wednesday morning, with Gov. Wolf at his side, Mayor Nutter reported that five people had died and that 65 people were taken to area hospitals, 54 of them to Temple University Hospital.
Herbert Cushing, chief medical officer at Temple, reported later that a sixth person, who had suffered a massive chest injury, had died. Eight other patients were in critical condition.
Train 188, bound to New York from Washington with 238 passengers and five crew members aboard, had left 30th Street Station minutes before the accident, which occurred near a curve at Wheatsheaf Lane and I-95.
Nutter told reporters the first fire call came in at 9:28 p.m. and quickly grew to four alarms. In all, he said, 33 pieces of equipment were sent in to help, along with 122 Fire Department personnel and Emergency Medical Services workers. Also responding were about 200 police officers, and officials from the Department of Homeland Security, Pennsylvania State Police, SEPTA, and Amtrak.
Because the train had already passed Philadelphia en route to New York, he said, it was likely that most passengers were either from Washington, New Jersey, or New York.
One of the passengers was 18-year-old Gaby Rudy, a student at George Washington University who had been sleeping in the last car when she felt it verge off the tracks and then flip over.
The car immediately began to fill with smoke, she said. She called 911. And then she saw another young woman on the floor. Her back was injured. Rudy said she helped her out of the train.
Rescuers told them they had to run across another set of tracks in case another train approached.
They walked into some woods while helicopters circled above.
Rudy, who had been on her way home to Livingston, N.J., called her dad. He was at Temple Hospital 90 minutes later to pick her up.
"She was very panicked and screaming," Daniel Rudy said. "It was the most traumatic thing imaginable."
Mayor Nutter said the rescue effort would continue throughout the morning.
"We will continue for some time out here with any continued search," he said. "Obviously, at 1 o'clock in the morning, in darkness, that is a more difficult obligation."
Efforts to comb through the wreckage using cranes and other heavy equipment would wait until daylight, he said.
By 2 a.m., the heavy equipment needed for that task had started to arrive.
A team of investigators was expected to arrive later Wednesday, Nutter said. He promised another update at 11 a.m.
Said Wolf: "Anything the state can do to help, we stand ready to do that. ... You can count on the commonwealth."
At an earlier news conference, Nutter described the scene as "an absolute, disastrous mess."
"We do not know what happened here," said Nutter, who arrived at the scene about 10:30. "We are not going to speculate about it."
"It is a devastating scene down there," Nutter said. "The engine completely separated from the rest of the train. ... It is incredible."
Initial reports indicated the train derailed as it entered the curve. An engine and all seven cars derailed, a U.S. Department of Transportation spokesman said early Wednesday.
"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," said acting Federal Railroad Administrator Sarah Feinberg.
The Federal Railroad Administration said it was sending at least eight investigators to the scene. The Transportation Department said it had officials at the site who would work with the National Transportation Safety Board.
SEPTA buses arrived at the accident scene to transport passengers who were not seriously injured.
At Aria Health-Frankford Campus, below the tracks of the Frankford El, Ede Sinkovics, 44, emerged early Wednesday morning shaking for a cigarette break before returning to hospital care.
Sinkovics, an artist in residence in Trenton, originally from Hungary, was hit in the chest and leg when the train's chairs dislodged from the force of impact.
"I was looking at my computer when I felt the car start to shake and the lights flipped, flashed," he said.
He held onto his seat to avoid being thrown about the cabin.
"Other people, they had broken mouth, there was loud screaming," he said.
Asked how he would get home, as a train passed overhead, Sinkovics said, "Not the train, no more trains."
Nearby Frankford Avenue was blocked with police tape and walls of police cruisers, SUVs, vans, and fire trucks. As police lights flashed and helicopters whirred, residents gathered on street corners to try to see anything they could.
Jeremy McTiernan, 36, has lived on the 3800 block of Frankford Avenue for about two months. He was outside his home with his roommate, smoking a cigarette, when he saw a blue flash _ and, moments later, another, much larger flash.
"I stood up," he said, thinking: "Man, that's something serious."
Still, he said, he heard nothing - no crash, no bang, no rumble. It wasn't until about three minutes later that the magnitude began to set in.
Dozens of emergency vehicles with flashing lights roared down his street - police cruisers, fire trucks, bike cops. He said within 15 minutes of the flash, there were 100 responders around his block, and dozens of vehicles.
Then he saw the passengers: people walking freely, toting luggage, seeming to laugh.
"Like they're getting off at a stop," McTiernan said.
A few minutes later, people came limping. Covered in soot and dirt. And after that, first responders helped walk out other passengers _ those who were bloody or couldn't walk on their own.
Eventually, more than a dozen people were on stretchers and flat boards in the street in front of his house, surrounded by emergency responders. McTiernan offered water, washcloths, and his bathroom to anyone who needed them.
A Marine who had served in Iraq, McTiernan had seen trauma before. Still, this scene was surreal.
"Pretty wild for a Tuesday night," he said.
Mary Barcellos of New York walked away from the train with her right shoe missing, leaving her foot bare. Other passengers around her limped and had grease-covered faces as police motioned them toward buses for the hospital. One man covered his bloodied face with a white cloth.
"It just tilted like you were going around a sharp curve, and then it just flipped all the way over," Barcellos said of the train.
She said the train landed upside down and jolted her to a window. She was lying on the window after the crash. The woman next to her had a broken leg, she said.
"I'm very lucky," Barcellos said, her glasses still intact.
Temple University Hospital remained on standby at 12:45 a.m. Wednesday, with doctors and nurses waiting outside the emergency room. Patients continued to arrive as late as 12:30 a.m., while people looking for loved ones were ushered into a waiting room.
Thomas Schultz, 31, who lives on Frankford Avenue in Port Richmond, and his fiancee were in line at the Walmart store at 2200 Wheatsheaf Lane when he thought he heard thunder.
"Everybody in the Walmart looked up," he said, adding that no one was alarmed.
Then, on the drive home, he saw about 20 police vehicles speeding toward the tracks.
He figured something was up. When he got home, he turned on the news and saw the disaster.
The area where the derailment occurred is normally under a speed restriction, requiring trains to slow down as they approach. The speed of Train 188 at the time of the accident was not immediately available.
The accident's effects on commuters were expected to stretch well into Wednesday. Amtrak's Northeast Corridor service was canceled Tuesday night, and SEPTA's Trenton and Chestnut Hill West lines were also scrapped, with Trenton service unlikely to resume Wednesday, the agency said.
Nutter said it was unlikely that service along the rail line would resume this week.
Former U.S. Rep. Patrick Murphy said he was sitting on a bench in the cafe car when the train began to topple.
"It went to my right, then to my left. Everyone who was on the left side of the car, where I was sitting, just got thrown completely over to the right side."
Murphy tweeted a photo from inside a wrecked train car. He said he was uninjured and trying to assist other passengers.
Murphy, an Iraq war veteran from Bucks County, said he helped around half of the people on the two cafe cars get out, then stayed with 11 others who couldn't.
"A lot of people panicked," he said. "Some seemed pretty bad. One guy couldn't move his leg at all." Another was unconscious.
U.S. Sen. Tom Carper (D., Del.) had been sitting just across from Murphy for most of the ride before getting off in Wilmington, Murphy said.
"I would have literally landed right on top of him, head first," Murphy said.
"I am grateful to be home safe and sound in Wilmington, and my heart goes out to all those on the train tonight," Carper said in a statement. "I hope all of those that are injured recover quickly, and I will keep them in my thoughts and prayers."
Jeremy Wladis was on the last car of the train when he felt the jolt. The 51-year-old New York man, who had been in Washington for work Tuesday, said he saw "phones, laptops, everything flying."
"There were women launched up in the luggage rack," he said about 11:45 p.m. at Webster School, where he and about two dozen others were being interviewed by the police and trying to find ways home. "I don't even know how they got there."
He said he and others helped the women down after the train came to a rest.
Daniel Wetrin, 37 of New York, said the initial shock was gentle, "compared to what came next."
"Within two seconds, it was chaos," he said.
The Rev. Tom Higgins, pastor at nearby Holy Innocents Church, was watching a hockey game when he heard the crash and walked to the scene to take a look. He spoke with police and then decided to go to Webster.
"I don't really know what I can do, but you want to try and comfort people if you can," he said. "Just sit with them and give them comfort."
Individuals with questions about friends and family who may have been on the train should call the Amtrak Incident Hotline 800-523-9101. Amtrak also has established a Family Assistance Center to work closely with family and friends of individuals on the train.
Contributing to this story were Inquirer staff writers Claudia Vargas, Ben Finley, Chris Palmer, Michael Boren, Allison Steele, Mike Newall, Jonathan Lai, Julia Terruso, Jonathan Tamari, Angelo Fichera, Tricia L. Nadolny, Laura McCrystal and Caitlin McCabe.