At this moment, Dr. Gridlock is in the vanguard of Washington Post coverage of this afternoon's train mishap in Northeast D.C. The item credits WJLA-TV and CNN for key facts on the accident.

Here's one commenter from the washingtonpost.com on the matter:

How is the Washington Post being scooped about a potentially serious metro rail collision? This happened about 45 minutes ago, and it's still in little print at the bottom of the Post web page. Come on guys. Surely you haven't all taken the buy out?

Comes this dispatch, via Dr. Gridlock:

A Red Line Metrorail train derailed at 5:10 p.m. approaching Fort Totten in the Shady Grove-bound side. Trains are turning back at Brookland and Takoma....Metro says that shuttle bus service has been requested to bridge the gap between Takoma and Brookland.

There are reports of injuries. Developing.

UPDATE, 5:35 P.M.: This seems quite a bit worse than a minor derailment. WJLA-TV reports:

Metro confirms two trains have collided on the Red Line between the Takoma and Fort Totten stations. It happened close to the Fort Totten station, a Metro spokesperson said.

D.C. Fire and EMS spokesman Alan Etter said one train was on top of the other train.

This is "developing into a mass casualty event," Etter said. "We're expecting a number of injuries. We're not aware of any fatalities at this point."

Update, 5:46 p.m.: ABC News/News Channel 8 is reporting one fatality. Reporter Brad Bell saw the fatality being taken from the accident scene. At least nine people injured. The fatality appears to be a male. Many passengers still stuck inside metro cars. Fire Department spokesman Alan Etter confirms one dead on WTOP.

Here is the official Metro alert:

"Metro reports that 2 train collided and one train is on top of the other train.  Metro reports massive injuries at this time. The green line and the red line are affected. Further information to follow."

It looks like the accident ocurred just beyond the Fort Totten stop.

Read More "Red Line Trains Collide Near Fort Totten: Deadliest Crash In Metro History" »