Thousands of homebound Metrorail passengers endured long delays traveling between the District and Virginia on Tuesday evening after a train derailed at the Rosslyn station, creating a severe bottleneck.
No injuries were reported after the derailment, which occurred shortly after 7 p.m., but all service passing through Rosslyn was suspended for 20 to 30 minutes. Metro then began single-tracking service.
Full service was restored by Wednesday morning.
Rosslyn is a key transfer point. Blue and Orange line tracks diverge just outside the station, and a switch sends trains on each of the lines in the proper direction. Switch points on rail systems are generally considered among the sections of track most vulnerable to derailment.
The cause of the derailment was not known immediately. Metro said it apparently involved only one set of wheels in the front car of a Blue Line train headed for Franconia-Springfield, which had just left the Rosslyn station. The six-car train was carrying about 1,000 people at the time. It was not known how close the train was to the switch.