At least nine people have been killed and 70 injured during a subway train collision in the United States.
Carriages of one train came to rest on top of the other after the collision near a station in Washington DC, officials said.
The female driver of the moving train - which crashed into the back of a stationary train - was among the dead.
The crash occurred above ground between Fort Totten and Takoma stations on the northeastern outskirts of the city near the border with Maryland about 5pm local time on Monday.
It is the worst crash in the 33 years of the Metro system and the first involving a passenger death since 1982 when three people were killed in a derailment.
Washington fire chief Dennis Rubin said approximately 200 firefighters were at the scene of the accident.
Mr Rubin said 76 people were treated at the scene and six of those were sent to hospital with critical injuries. He said the majority were walking wounded.
The dead driver was named as Jeanice McMillan, 42, by the Associated Press and the Washington Post.