1 dead, half-dozen taken to hospitals after smoke empties DC Metro station

Metro Transit Police officers secure the entrance to L’Enfant Plaza Station in Washington, Monday, Jan. 12, 2015, following an evacuation. Metro officials say one of the busiest stations in downtown Washington has been evacuated because of smoke. Authorities say the source of the smoke is unknown. (AP Photo/Manuel Balce Ceneta) (The Associated Press)

A Metro Transit Police officer walks up the escalator at L’Enfant Plaza Station in Washington, Monday, Jan. 12, 2015, following an evacuation. Metro officials say one of the busiest stations in downtown Washington has been evacuated because of smoke. Authorities say the source of the smoke is unknown. (AP Photo/Manuel Balce Ceneta) (The Associated Press)

Reynaldo Hernandez holds a cloth over his smoke covered face as he coughs deeply after being evacuated from a smoke filled metro subway tunnel in Washington, Monday, Jan. 12, 2015. Metro officials say one of the busiest stations in downtown Washington has been evacuated because of smoke. Authorities say the source of the smoke is unknown. (AP Photo/Jacquelyn Martin) (The Associated Press)

A spokeswoman for the metro system in Washington, D.C., says one person has died after smoke forced the evacuation of one of the U.S. capital's busiest downtown stations.

Spokeswoman Caroline Laurin declined to give more information Monday evening, saying the National Transportation Safety Board was investigating.

Hundreds were evacuated from the L'Enfant Plaza station about 3:30 p.m. Monday. At least six were taken to the hospital.

District of Columbia Fire and EMS spokesman Timothy Wilson said earlier in the day that emergency medical workers evaluated dozens of passengers after smoke filled the station.

The source of the smoke was not immediately known.