Suicide by subway train is a problem for transit agencies around the world, not just Metro. It's also a problem for railroads that have even faster moving trains on open sections of track.
But experts don't know how many people use trains to kill themselves because some agencies don't report the numbers.
New York City's subway system, for example, says it does not track the numbers of suicides because the New York City Police Department is in charge of all investigations. A police spokesman, meanwhile, said he doesn't believe the agency tracks those numbers, either, it focuses on homicides.
Some deaths are also hard to categorize, such as those on remote railroad tracks where no one sees the death.
Still, Alan Berman, a psychologist who leads the American Association of Suicidology, estimates that 300 to 400 people use transit or railroad systems to kill themselves in the United States each year.
The deaths represent about 1 percent of all suicides nationwide.
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