NEW YORK (CNN) — Even though the train was careening around a curve, Amanda Swanson felt the wreck in slow motion.
All seven passenger cars jumped the tracks. The windows of the coaches broke out. Then, "gravel came flying up in our faces," said Swanson, 26.
"I really didn't know if I would survive," she said. "The train felt like it was on its side and dragging for a long time."
Swanson, a waitress who was on her way to work at a Midtown Manhattan restaurant, put her bag in front of her face to block the rubble as the car she was riding in flipped over.
"I just closed my eyes and kind of hoped to God that I was going to be able to call my mom with decent news."
Eventually, the car she was in came to a stop with a thud. "I couldn't see anything. It was just smoke," she told CNN's "New Day."
As the dust settled, she saw fellow passengers staggering out of the train and heard them moaning for help.
Swanson managed to get off the train carrying her cell phone, its screen shattered but still working.
But four others died and at least 67 were injured after the train derailed Sunday morning in the Bronx, about 10 miles north of Manhattan's Grand Central Terminal. The train was coming from Poughkeepsie with about 150 people on board.
Three of the dead were thrown out of the train as it "came off the track and was twisting and turning," New York Fire Department Chief Edward Kilduff told reporters.
One car skidded to a stop just feet away from the Harlem River.
People who live near the tracks looked on as rescuers searched for survivors and investigators combed the wreckage.
"It was a scene straight out of a sci-fi movie," said Beth Barret, who sent photos to CNN's iReport. "Very surreal and very scary."
Early Monday morning, workers began uprighting the cars to the extent that safety officials would allow, a spokesman for Metro North Railroad said.
"The first to be re-railed will be the locomotive, which is expected shortly," Aaron Donovan said.
A dangerous turn
Investigators have recovered two event recorders -- one from the locomotive at the back of the train and one from the car at the front.
They've downloaded the information from one of them, National Transportation Safety Board spokesman Keith Holloway said, and the other one is on the way to Washington for analysis.
Authorities are looking for video that may have captured the derailment, he said.
It's not the first time a train jumped the tracks on that turn. A freight train derailed in the same curve in July, damaging about 1,500 feet of track, the Metropolitan Transit Authority reported at the time.
"That is a dangerous area on the track just by design," New York Gov. Andrew Cuomo said after Sunday's crash. "The trains are going about 70 miles an hour coming down the straight part of the track. They slow to about 30 miles per hour to make that sharp curve ... where the Hudson River meets the Harlem River, and that is a difficult area of the track."
National Transportation Safety Board member Earl Weener said the agency would look into whether there was any connection between that derailment and Sunday's crash, but both he and Cuomo discounted the possibility.
"The curve has been here for many, many years, right, and trains take the curve every day, 365 days a year ... We've always had this configuration. We didn't have accidents," Cuomo said. "So there has to be another factor, and that's what we want to learn from the NTSB."
The train operator, who is among the injured, told investigators he applied the brakes, but the train didn't slow down, said a law enforcement official who was on the scene and is familiar with the investigation.
"That will be a key point of concern, whether this train was moving too quickly," said Joe Bruno, New York's commissioner of emergency management.
Mary Schiavo, a former inspector general for the U.S. Department of Transportation, said investigators should take a close look at the sharp curve.
"It has been there forever, but the fact that we've had other accidents there means we have to look beyond just the fact that the train engineer said that brakes were not working," she said. "We have to see if there's additional issues concerning that track."
The MTA identified those killed as Donna L. Smith, 54, of Newburgh, New York; James G. Lovell, 58, of Cold Spring, New York; James M. Ferrari, 59, of Montrose, New York; and Ahn Kisook, 35, of Queens, New York.
Lovell did freelance audio and was headed into New York to work Sunday morning, said Dave Merandy, a town council member in the Hudson Valley community of Philipstown.
"He loved his family and did what was necessary to keep things afloat with his family. He was a great man," Merandy said.
At least 67 people were injured, Bruno said. One suffered a spinal cord injury that could leave him paralyzed from the neck down, said Dr. David Listman, director of the emergency department at St. Barnabas Hospital in the Bronx.
The man is the father of a 14-year-old who was released from the hospital Sunday.
"It's hard to understand how they were sitting next to each other on the train, and the son walks away with minor bruises, and the father sustained such a severe injury," Listman said.
While patients with severe fractures could be released from the hospital Monday, he said, they may require further treatment and mental health care after surviving the devastating accident.
"For a lot of these people, the train was their way of commuting to work. I think a lot of these people are going to have to contend with getting back to normal life," he said. "I think that's going to be very difficult for them."
The Metro-North Hudson Line had a ridership of 15.9 million last year, with hundreds of people on packed trains during weekday rush hour, officials said.
The governor advised Monday morning drivers in the area to plan for a long commute or use the Harlem Line, which runs roughly parallel to the damaged Hudson Line.
On Sunday, service was suspended on part of the Hudson Line and won't resume until the NTSB finishes documenting the scene and returns the track to the MTA for repairs, Cuomo said.
Officials hope to get train service on the line up and running again by the end of the week, he said.
Weener said the NTSB hopes to interview the conductor and the engineer either Monday or Tuesday.
"That, combined with the data from the event recorders, will give us a pretty good insight into what was going on."
Swanson told "New Day" that she's also looking for answers.
"I definitely want to know how and why this happened. ... Obviously there was an error. Something went wrong," she said. "I just hope everybody that needed help got the help they needed."
CNN's Eden Pontz reported from New York. CNN's Holly Yan and Catherine E. Shoichet reported from Atlanta. CNN's AnneClaire Stapleton, Rene Marsh, Kate Bolduan, Polina Marinova, Lorenzo Ferrigno, Alexandra Field, Kristina Sgueglia, Jon Auerbach, Dana Garrett, Shimon Prokupecz, Joe Johns and Mike M. Ahlers contributed to this report.