Updated

Officials investigating Washington D.C.'s worst subway accident, which left at least nine dead, are eyeing whether the failure to upgrade old trains with key recording devices designed to prevent such collisions contributed to the crash.

The train that triggered the accident wasn't equipped with the recorders, said National Transportation Safety Board member Debbie Hersman. It was part of an old "thousand-series" fleet that was not outfitted with the technology, she told reporters Tuesday at a news conference.

The NTSB had previously recommended that all trains have the recorders installed.

The train that was struck, however, did have the recording devices — which will provide valuable information that could point to why the crash occurred, according to Hersman.

Metro officials planned to replace the old trains, but were years away from putting new ones into operation.

Federal investigators also are reviewing cell phone records to see whether texting was a factor in the accident.

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The Metrorail collision at the height of the evening rush hour Monday happened when one train heading into D.C. from Maryland slammed into the back of another.

At least nine died, according to Metro General Manager John Catoe, and at least 70 others were wounded.

Metro officials said two men and seven women, all adults, were killed.

The following five victims were identified: Jeanice McMillan of Springfield, Va., the operator of the train that triggered the crash; and passengers Mary Doolittle, 59, of Washington; Ana Fernandez, 40, Hyattsville, Md.; Dennis Hawkins, 64, of Washington; and Lavanda King, 23, of Washington.

McMillan was hired in March 2007 as a bus driver.

Rescue crews worked through the night and into Tuesday to recover more victims. The wreckage of the mangled trains was dismantled on Tuesday.

It was the worst crash in the Metro's 33 years of service shuttling tourists and commuters around Washington and to the Maryland and Virginia suburbs.

Hersman said in an interview with The Associated Press that the NTSB warned in 2006 that there were safety problems related to trains rolling back on their tracks.

"When the train rolled back, the operator was not able to stop it," she said.

The NTSB recommended that a specific series of cars be phased out or retrofitted to make them more crashworthy, she added.

"We saw that they did not do well against the newer series of cars as far as crash-worthiness," Hersman said.

The Metrorail transit system "was not able to do what we asked them to do," which was to either to retrofit the thousand-series or phase them out, she said.

It was not known whether the trains involved in Monday's crash were in the series that were recommended for replacement or retrofitting.

One survivor of the crash, Jamie Jao, told FOX News that he was sitting in the front of the train that struck the other subway.

"The actual crash itself happened very fast," he said. "It was a very loud noise, like an explosion. I saw things breaking apart in front of my eyes. ... I was on top of the other train. My shoes disappeared."

Jao said rescuers helped him out to safety, but he could no longer see some of the other passengers who had been sitting near him. Aside from a foot injury, he escaped unscathed.

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Washington D.C. Mayor Adrian Fenty said that 76 people were injured and taken to hospitals on Monday. Two victims were in critical condition, he said.

"It is a scene of real devastation," Hersman said. Passenger cars were sliced open when the trains smashed together.

During the evening rush hour, one train was stopped on the tracks, waiting for another to clear the station ahead, when a trailing train plowed into it from behind, Catoe said.

Catoe said an automated computer system used to run trains was supposed to keep them apart, but it was not clear whether the system was in use when the crash occurred.

Metro has a computerized system on most trains during rush hour that is supposed to control braking, speeds and prevent collisions. The system, however, has failed before.

In June 2005, in a tunnel under the Potomac River, a train operator noticed he was getting too close to the train ahead of him even though the system indicated the track was clear. He hit the emergency brake in time, as did the operator of another train behind him.

Metro spokeswoman Candace Smith didn't know the outcome of the investigation into that incident, which she called "highly unusual."

People inside some of the cars were banging on the windows trying to get out, said Jervis Bryant of Upper Marlboro, Md., who was in the area at the time.

Bryant said he ran over to help, but couldn't get close enough to reach the passengers. He said some eventually began exiting the trains.

"It's a scene I never thought I would see," said Bryant, who frequently rides the Metro. "It was more frightening to watch and not to be able to help."

More than 200 firefighters from D.C., Maryland and Virginia eventually converged on the scene. Sabrina Webber, a 45-year-old real estate agent who lives in the neighborhood, said she raced to the scene after hearing a loud boom like a "thunder crash" and then sirens. She said there was no panic among the survivors.

The crash around 5 p.m. took place on the system's red line, Metro's busiest, which runs below ground for much of its length but is at ground level at the accident site near the Maryland state line in northeast Washington.

The crash Monday occurred on the outskirts of the city in an area where higher train speeds are common because there is a longer distance between stops. Trains can go 55 to 59 miles per hour, though the train's speed has not yet been determined.

Each train had six cars and was capable of holding as many as 1,200 people. Hersman said the trains were bound for downtown. That would mean they were less likely to be filled during the afternoon rush hour.

The trains had pulled out of the Takoma Park station and were headed in the direction of the Fort Totten station.

Passenger Maya Maroto, 31, was riding on McMillan's train.

"We were going full speed — I didn't hear any braking. Everything was just going normally. Then there was a very loud impact. We all fell out of our seats. Then the train filled up with smoke. I was coughing," Maroto said.

Maroto said there was confusion after the impact because no announcements were immediately made. She said some passengers wanted to climb out, but others were afraid of being electrocuted by a rail.

Tijuana Cox, 21, was in the train that was hit. She had her sprained arm in a sling Tuesday.

"Everybody just went forward and came back," with people's knees hitting the seats in front of them, said Cox.

The only other fatal crash in the Metro subway system occurred Jan. 13, 1982, when three people died as a result of a derailment. That was a day of disaster in the capital: Shortly before the subway crash, an Air Florida plane slammed into a bridge immediately after takeoff from Washington National Airport. The plane crash, during a severe snowstorm, killed 78 people.

In January 2007, a subway train derailed in downtown Washington, sending 20 people to the hospital and prompting the rescue of 60 others from the tunnel. In November 2006, two Metro track workers were struck and killed by an out-of-service train. An investigation found that the train operator failed to follow safety procedures. Another Metro worker was struck and killed in May 2006.

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The Associated Press contributed to this report.