*Four deaths confirmed, including one train operator
*Part of one train on top of the other after collision
*Rescuers seeking to remove additional passengers (adds background, quote, details)
By Andy Sullivan
WASHINGTON, June 22 (Reuters) - Four people were killed and at least 70 were injured when a Washington, D.C., subway train derailed and smashed into another train on the outskirts of the city during the afternoon rush hour on Monday, officials said.
Washington D.C. Mayor Adrian Fenty, giving the number of those killed, called the crash the deadliest in the history of the city’s “Metro” train subway system.
The city’s fire chief said 70 people had been treated for injuries so far.
Several mangled cars of one train were lying on top of the other train on open-air tracks, and emergency worked propped ladders against train doors to rescue people.
The Washington Metropolitan Area Transit Authority, which runs the subway system, said a six-car Red Line train derailed and collided with another train at about 5 p.m. EST/2100 GMT.
The transit authority said one of those killed was a female train operator.
“The incident is under investigation but it appears that the trains were on the same track and the operator who was killed was on the trailing train,” it said.
The accident trapped passengers in one or more of the subway cars.
Emergency rescue personnel worked to free the passengers, while others carried injured people off the trains on stretchers.
“We are working to first get everyone outside of the train and everyone who needs medical attention will get (it),” the general manager of metro system, John Catoe, told reporters.
The accident occured between Fort Totten and Takoma stations on the northeastern outskirts of the city near the border with Maryland.
One witness described how one train appeared to collide with and then run up and over the second train.
“It was very mangled, everything is ripped out of there,” the woman, who was not identified, told the local ABC television affiliate.
Ladders were placed along the wreckage as rescue workers examined the wreckage and used cutting devices to free those trapped inside.
A reporter with Fox television’s local news affiliate said he saw what appeared to be a body covered with a sheet, and several injured passengers including one wearing a neck brace.
The subway system is heavily used to get in and around the U.S. capital.
The Metrorail and Metrobus services serve a population of 3.5 million people within an area of 1,500 square miles (3,890 square km). The subway had a total of 215.3 million trips in the last fiscal year.
Additional reporting by Washington Bureau, Writing by Andrew Quinn, Editing by Frances Kerry