Note the distance between the doors.

This just in 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.

You Orange line folks are really having a bad time of it lately.

We’re trying to get more information on the derailment. If you’re near that part of Arlington, tell us what you see happening.

UPDATE 3:50 p.m.:Reader Sarah sends in phone snapshots from her friend who is stuck on the derailed train. “My friend has been sending me texts. He’s stuck and there’s no air conditioning. Apparently they’re sending a rescue train momentarily,” Sarah wrote in an email. Photos from her friend are below. From the looks of things, it’s relatively calm, if no doubt really hot, down there.

UPDATE 3:58 p.m.: More from WMATA:

Rail officials are using a second train to get the passengers off of the incident train by backing the second train up to the incident train to off-load the passengers.

Free shuttle buses are being set up at the Foggy Bottom, Virginia Square and Court House stations along the Orange Line … but given that Metro is advising that customers can expect lengthy delays for those shuttles, we’d recommend starting trying to figure out an alternative for your evening commute right now.

UPDATE 4:07 p.m.: Another text from Sarah’s friend Mike: “Awesome. On rescue train. Have been for 15 min. It isn’t moving.” Hang in there, stranded passengers!

UPDATE 5:06 p.m.: Metro says stranded passengers were taken to the Court House station at about 4:25 p.m., and that no injuries have been reported. A pregnant woman, however, was taken to a local hospital for observation.

Car 2000, the third car of Train 905, experienced the derailment between Rosslyn and Court House when the front wheels came off the track.

Trains continue to share one track between Clarendon and Foggy Bottom.

Metro officials said they have notified the Tri-State Oversight Committee and the National Transportation Safety Board of the incident.

“We will be calling our best people together from our Departments of Safety, Rail and Track to determine the cause of the derailment,” Metro General Manager John Catoe said. Officials said it will take several days before they know the cause of the derailment.

WMATA’s web site appeared to be down for at least ten minutes in the aftermath of the derailment, but it’s back up now.