BALTIMORE (WJZ)  Metro train service was affected for more than 12 hours following a train derailment in downtown Washington, D.C. Monday morning.

Officials say the derailment was likely caused by a broken rail — an accident that could have very easily been deadly.

“We felt something. It could have been running over some debris or there could have been a real issue — I don’t know. But it was definitely an unusual feeling,” one rider said. “The train continued until it was able to stop, the lights went out, and it kind of got a little smokey with burnt rubber.”

The city’s Metro rail system tweeted that the derailment happened around 6:40 a.m. The train carrying 63 passengers derailed shortly after leaving the Farragut North station.

Fire and EMS crews worked to evacuate the passengers, all of which were uninjured.

“It wasn’t an urgent need to get people out there quickly, they did it very methodically and the fact that there were no injuries obviously on the train but even leaving the train, in a tunnel, is just a testament that they made the right decision,” a Metro official said.

Metro says it was a 7,000 series rail car that went off the tracks in one of the oldest sections of the system, and at least three of the eight cars derailed.

“It is our responsibility that our fire and emergency medical service responded quickly and evacuated riders safely, and that’s exactly what happened today,” D.C. Mayor Muriel Bowser said.

Despite the smoke, Metro says no fire was involved with the derailment.

Late Monday afternoon, Metro brought in a machine to get the derailed train back on track. Investigators are now honing in on track infrastructure as the possible cause. Federal investigators remained on the scene Monday night.

Red Line service continued to experience delays with single tracking into the evening. Shuttle buses were running in place of trains in both directions after the crash.

Follow @CBSBaltimore on Twitter and like WJZ-TV | CBS Baltimore on Facebook