The video shows the train — which was roughly 662 feet long — passes the camera in just over five seconds. But AP found that the surveillance video plays back slightly slower than in real time.

So, adjusting for the slower playback puts the train’s estimated speed at 107 miles per hour. The surveillance camera was located at a site just before the bend in the tracks.

The crash killed seven people and injured more than 200.

Updated 1:55 p.m.: Philadelphia police officials say the engineer of the Amtrak train that crashed, killing seven people and injuring more than 200, declined to provide a statement to investigators.

They say the engineer also had an attorney when he left a meeting with investigators. The engineer has not yet been identified.

Investigators are trying to determine why the train slipped off the tracks while rounding a sharp curve Tuesday night northeast of Philadelphia’s city center.

Authorities say the locomotive’s data recorder has been recovered and that it should yield critical information, including the speed of the train.

The speed limit just before the curve was 70 mph and on the curve it was 50 mph.

City officials are holding another briefing Wednesday afternoon. The National Transportation Safety Board also plans a 5 p.m. briefing.

Updated 1:45 p.m.: A 20-year-old U.S. Naval Academy midshipman from New York City is one of the seven people killed in Tuesday’s Amtrak train derailment in Philadelphia.

Navy Secretary Ray Mabus identified the midshipman as Justin Zemser.

The popular student leader and athlete was on leave from the Annapolis, Maryland, institution and heading home to Rockaway Beach, New York.

Zemser and his family were temporarily forced from the community by Superstorm Sandy in 2012.

He was elected student government president at Channel View High School and was a two-time letter winner on the school’s football team.

He played sprint football, a form of the sport for players under 172 pounds, at the Naval Academy.

Updated 1:20 p.m.: The Federal Railroad Administration says Amtrak inspected tracks in Philadelphia just hours before a deadly derailment and found no defects.

The agency says the speed limit on the track just before the accident site is 70 mph, and 50 mph for the curve near where the train came to a rest.

The New York-bound train derailed in Philadelphia on Tuesday night, killing at least seven people and injuring 200 others.

Federal authorities will look at a variety of evidence as they try to pinpoint the cause. A former head of railroad accident investigations at the National Transportation Safety Board, Bob Chipkevich, says they’ll focus on the train’s event data recorder, video recordings and the condition of the rails, rail ties and train cars.

UPDATED: 1:13 P.M.: Another body has been pulled from the wreckage of an Amtrak train derailment in Philadelphia, increasing the death toll to seven.

Philadelphia Fire Department Executive Chief Clifford Gilliam says the body was found Wednesday as crews combed through the mangled train.

Authorities previously confirmed the deaths of six people. They include an Associated Press employee and a U.S. Naval Academy midshipman.

Rescue crews are searching the mangled wreckage as investigators try to determine why the train hurtled off the tracks.

The train was carrying 238 passengers and five crew members as it headed from Washington to New York City along the nation’s busiest rail corridor.

PHILADELPHIA — Rescue crews searched the mangled wreckage for victims Wednesday as investigators tried to determine why an Amtrak train jumped the tracks in a crash that killed at least six people, injured more than 200 and plunged screaming passengers into darkness and chaos.

Investigators recovered the train’s data recorders and said they expected them to yield crucial information, including how fast the train was going as it rounded a sharp curve and derailed in the city’s working-class Port Richmond section shortly after 9 p.m. Tuesday.

“It’s a devastating scene. There are many first responders out there. They are working. They are examining the equipment, seeing if there are any more people in the rail cars,” Robert Sumwalt of the National Transportation Safety Board said.

Mayor Michael Nutter said some people remained unaccounted for, raising fears the death toll could rise, though he cautioned that some passengers listed on the Amtrak manifest might not have boarded the train, while others might not have checked in with authorities.

“We are heartbroken by what has happened here,” he said.

Train 188, a Northeast Regional, was en route from Washington to New York when it lurched to the right and fell off the tracks at a notorious curve not far from the scene of one of the nation’s deadliest train wrecks more than 70 years ago.

The conductor survived and was expected to give a statement to police. The train also had a video camera in its front end that could yield clues to what happened, Sumwalt said.

Passengers scrambled through the windows of toppled cars to escape. One of the seven cars was severely mangled. Hospitals treated more than 200 people for injuries that included burns and broken bones.

The accident closed the nation’s busiest rail corridor between New York and Washington as federal investigators arrived to begin examining the twisted wreckage, the tracks and the signals.

Passenger Jillian Jorgensen, 27, was seated in the quiet car — the second passenger car — and said the train was going “fast enough for me to be worried” when it began to lurch to the right.

The train derailed, the lights went out and Jorgensen was thrown from her seat. She said she “flew across the train” and landed under some seats that had apparently broken loose from the floor.

Jorgensen, a reporter for The New York Observer who lives in Jersey City, New Jersey, said she wriggled free as fellow passengers screamed. She saw one man lying still, his face covered in blood, and a woman with a broken leg.

She climbed out an emergency exit window, and a firefighter helped her down a ladder to safety.

“It was terrifying and awful, and as it was happening it just did not feel like the kind of thing you could walk away from, so I feel very lucky,” Jorgensen said in an email to The Associated Press. “The scene in the car I was in was total disarray, and people were clearly in a great deal of pain.”

Early Wednesday, authorities on the scene seemed to be girding for a long haul. Several portable toilets were delivered for investigators and recovery workers. Heavy equipment was brought in, and Amtrak workers in hard hats walked around the wreck.

All seven train cars, including the engine, were in “various stages of disarray,” Nutter said. He said there were cars that were “completely overturned, on their side, ripped apart.”

An AP Press manager, Paul Cheung, was on the train and said he was watching a video on his laptop when “the train started to decelerate, like someone had slammed the brake.”

“Then suddenly you could see everything starting to shake,” he said. “You could see people’s stuff flying over me.”

Cheung said another passenger urged him to escape from the back of his car, which he did. He said he saw passengers trying to get out through the windows of cars tipped on their sides.

“The front of the train is really mangled,” he said. “It’s a complete wreck. The whole thing is like a pile of metal.”

Gaby Rudy, an 18-year-old from Livingston, New Jersey, was headed home from George Washington University. She said she was nearly asleep when she suddenly felt the train “fall off the track.”

The next few minutes were filled with broken glass and smoke, said Rudy, who suffered minor injuries. “They told us we had to run away from the train in case another train came,” she said.

Another passenger, Daniel Wetrin, was among more than a dozen people taken to a nearby elementary school.

“I think the fact that I walked off kind of made it even more surreal because a lot of people didn’t walk off,” he said. “I walked off as if, like, I was in a movie. There were people standing around, people with bloody faces. There were people, chairs, tables mangled about in the compartment … power cables all buckled down as you stepped off the train.”

Several people, including one man complaining of neck pain, were rolled away on stretchers. Others wobbled as they walked away or were put on buses. An elderly woman was given oxygen.

The Port Richmond neighborhood is a mix of warehouses, industrial buildings and homes.

The area where the wreck happened is known as Frankford Junction. It is not far from the site of the 1943 derailment of the Congressional Limited, from Washington to New York, which killed 79 people.

Amtrak’s busy Northeast Corridor between Washington and Boston serves 11.6 million passengers a year.

The mayor, citing the mangled train tracks and downed wires, said: “There’s no circumstance under which there would be any Amtrak service this week through Philadelphia.”