Normal service resumed at 10:30 a.m. Tuesday after a Metro train derailed in Washington, D.C. early Monday, forcing 63 people to walk through a tunnel for the length of two football fields and disrupting train service downtown for hours.
Multiple cars of a train on the Red Line crashed off the tracks near the Farragut North station about 6:30 a.m. No one was hurt, but the accident startled dozens of passengers.
Trains along the line shared a track between Judiciary Square and Farragut North for much of Tuesday morning, but just before 11 a.m., Metro announced that trains were no longer single-tracking.
Local and federal investigators are working to determine what caused the train to derail.
A Big-Picture Look at the Metro Derailment
"The investigators are focusing on the track infrastructure," Metro GM and CEO Paul J. Wiedefeld said.
The track was manufactured in 1993, which Wiedefeld described as not excessively old.
A section of the rail was removed for forensic analysis by a third party, Metro said.
Investigators will inspect the train for mechanical failures, and they're talking to the operator, who was removed from service and tested for drugs and alcohol, which is standard procedure after a derailment.
Recent tests, including sonic testing, showed no issues with the stretch of track.
The area was not part of Metro's SafeTrack maintenance project.
"If you work in the transit industry, you recognize that no system is immune from the hazard of a broken rail," Metro Chief Safety Officer Pat Lavin said. "It is infrequent but not uncommon."
Rider Gavin Bowman said that during the derailment he felt a violent shake and then a bang.
"It was about twice as bad as any turbulence I've been in on a plane," Bowman said. "Scraping metal, concrete breaking."
Photos from a man who was on board the train show people walking through a tunnel.
Right after the derailment, officials spoke about "loose rail" and communications problems, audio obtained by News4 reveals.
"He said it seemed like a derail," a man can be heard saying. "He said all of a sudden, smoke just came out of nowhere."
RAW VIDEO: Metro GM Speaks About Derailment, Expected Delays
"We might have hit some rail -- some loose rail," another man says. "We are obviously stuck in the tunnel. There's no radio transmission on my radio, or phone reception."
Metro said there were radio coverage issues in the area of the derailments which they expect to fix by Wednesday. The radio system D.C. Fire and EMS used during its response worked, according to Metro.
The incident occurred days after the third anniversary of the Metro accident Jan. 12, 2015, that killed 61-year-old Carol Inman Glover. Dozens of people choked on smoke that filled a train stopped in a tunnel near L'Enfant Plaza.
The train that derailed is one of the newest trains in the Metro system, in the 7000 series, D.C. fire department official David Faust said. Three of its eight cars derailed.
A Metro Transit Police officer was on the train during the derailment Monday, Metro spokesman Dan Stessel said. The officer and train operator went into each car to check on passengers, Stessel said.
Passengers were on the train about 90 minutes before they were evacuated through a tunnel.
"We just had to sit there," passenger Lilly Huezo said. "It just took awhile."
Metro said the passengers had to walk about 200 yards through a tunnel to evacuate. The path was well-lit, and it was considered a non-emergency evacuation, Faust said.
The evacuation was conducted with safety in mind, not speed, and no one was injured, according to Metro.
"We took our time and did it as safely as possible," Faust said. "It was warmer in the tunnel than it was up here on the street."
Passengers exited through the Metro Center station, officials said.
Officials Aren't Sure What Caused Red Line Derailment
The train had fewer passengers than it would on a typical Monday morning, during rush hour, because of the Martin Luther King Jr. Day holiday.
Metro service was suspended in the area of the derailment for hours Monday morning. Trains were delayed and single-tracking in both directions between Judiciary Square and Farragut North.
Fire and EMS officials blocked several streets in the area of 12th Street and G Street.
Metro Passengers Describe Moment Their Train Derailed
Metro Board Chairman Jack Evans said he hopes dedicated finding for Metro from Maryland, Virginia and the District will be approved by spring.
"Dedicated funding will allow us to have the money then to do the necessary repairs over the next 10 years," he said. "Again, I'm not talking about getting this done by the end of the summer. We're talking 10 years."
Evans scheduled a safety hearing for the board's Jan. 25 meeting.
Stay with News4 for more on this developing story.