NEW YORK (CNN) -- The commuter train involved in a deadly weekend derailment in the Bronx was doing 82 mph as it entered the 30-mph curve where it jumped the tracks, federal safety officials said Monday.
The National Transportation Safety Board reported that figure based on preliminary data from the event recorders taken from the locomotive and another car, NTSB member Earl Weener told reporters. The data showed the engineer cut the throttle six seconds before the locomotive came to rest and applied the brakes five seconds before, a move Weener said came "very late in the game."
But the engineer, William Rockefeller, and the rest of the train crew were still being questioned Monday afternoon, and the cause of the derailment has not yet been determined, Weener said.
"This is raw data off the event recorders, so it tells us what happened. It doesn't tell us why it happened," Weener said.
Four people died in the Sunday morning crash on New York's Metro-North commuter line, about 10 miles north of Manhattan's Grand Central Terminal. At least 67 more were hurt.
The train's recorded speed is not only far faster than the rated speed for the curve where the derailment occurred, it's faster than the 70 mph posted for the section of track that led into the curve, Weener said.
U.S. Sen. Chuck Schumer, who appeared with Weener, said the speed report "sort of takes your breath away."
"For a train to be going 82 mph around that curve is just a frightening thought," said Schumer, D-New York. "The fact that it was going 82 mph even in the 70-mph zones before the curve started raises so many questions and is scary."
Investigators have seen no indication of brake problems, Weener said. Schumer said the tracks appear to have been in good shape, and the preliminary indication is that signals were working properly -- "but it's premature to blame anyone or anything right now," he added.
Despite the high speed, surviving passenger Amanda Swanson said she felt the wreck in slow motion.
All seven passenger cars jumped the tracks, the windows of the coaches broke out and 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 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 and skidded to a stop with a thud.
"I couldn't see anything," she told CNN's "New Day." "It was just smoke."
As the dust settled, she saw fellow passengers staggering out of the train and heard them moaning for help.
"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," she said. Swanson managed to get off the train carrying her cell phone, its screen shattered but still working.
Workers began lifting the rail cars back onto the tracks Monday. Police cadaver dogs made a final sweep of the scene. Doctors treated wounded victims. And federal investigators combed the wreckage, searching for the answer to a key question: What caused the deadly derailment?
Beth Barret, who sent photos to CNN's iReport, called the scene "very surreal and very scary."
"It was a scene straight out of a sci-fi movie," Barret said.
A dangerous turn
The recorders will answer important questions for investigators about how fast the train was traveling and whether its brakes were working, said Peter Goelz, a former managing director of the NTSB.
From there, he said, authorities will likely zero in on several questions: Was the train's driver rested? Was he paying attention to his job? And did the equipment on the train function correctly?
Authorities also are looking for video that may have captured the derailment, safety board spokesman Keith Holloway said. Railroad officials have said there were no video cameras aboard the train. But if there's security camera footage in the area, that could give clues to investigators, Holloway 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.
Weener said the agency would look into whether there was any connection between that derailment and Sunday's crash, but both he and New York Gov. Andrew 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."
Official: Engineer said brakes didn't work
Rockefeller told investigators he applied the brakes, but the train didn't slow down, according to a law enforcement official who was at 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."
Metro-North Railroad inspects its tracks twice a week, spokeswoman Marjorie Anders said. The most recent inspection found the track was "OK for normal operations."
She said the train wasn't equipped with positive train control -- a high-tech system designed to slow down or stop trains to prevent crashes caused by human error.
Anders said the railroad conducted routine drug and alcohol tests on crew members but has not released the results.
Rockefeller appeared coherent at the scene, and there was no indication he was intoxicated, said a high-ranking law enforcement official who is part of the investigation.
The engineer could not be immediately reached for comment.
Anthony Bottalico, general chairman of the union that represents Rockefeller and the train's conductors, said the crew members are also eager to find out what caused the crash and "make sure it doesn't ever happen again."
"Hopefully over the next day or two, there will be some kind of idea or closure," he said.
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 boy 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."
One of train's assistant conductors has a broken collarbone, a head injury and bruises all over her body, Bottalico said.
The train's conductor suffered a head injury, he said, but was scheduled to meet with investigators Monday.
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 commuters in the area to plan for a long journey or use the Harlem Line, which runs roughly parallel to the damaged Hudson Line.
On Sunday, there were about 150 people on board when the train derailed.
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.
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 Alexandra Field reported from New York. CNN's Holly Yan and Catherine E. Shoichet reported from Atlanta. CNN's Eden Pontz, AnneClaire Stapleton, Rene Marsh, Kate Bolduan, Wolf Blitzer, Polina Marinova, Lorenzo Ferrigno, Alexandra Field, Kristina Sgueglia, Jon Auerbach, Dana Garrett, Shimon Prokupecz, Mike M. Ahlers and Haley Draznin contributed to this report.
™ & © 2013 Cable News Network, Inc., a Time Warner Company. All rights reserved.