This from Metro:

A six-car Orange Line train headed in the direction of Vienna derailed at about 2:45 p.m. today. The third car of train 905, with an unknown number of passengers on board, experienced the derailment between Rosslyn and Court House Metrorail stations. Emergency crews are on the scene. There are no reports of injuries at this time.

Trains are sharing one track (single-tracking) between Clarendon and Foggy Bottom Metrorail stations. The Blue Line is operating regular service.

Customers can expect major delays on the Orange Line throughout the remainder of the day.

This, less than a week after downed power lines near Falls Church shut down the orange line in both directions. Anyone out there know how bad this is yet?

UPDATE: A second train is now backed into the derailed train and is being used to get the passengers off. Shuttles are trying to handle the rush-hour backups.