Deadly DC Metro Smoke Incident under Investigation

National Transportation Safety Board investigators are looking for answers Tuesday after one of the busiest metro stations in Washington, D.C., filled with smoke, killing one person.

On Monday, a yellow line train was evacuated after smoke filled the L'Enfant Plaza Metro station around 3:30 p.m.

"It started to get scary pretty quick," passenger Jonathan Rogers told the Washington Post. "People started praying. Smoke was coming in pretty steadily."

Thirty-eight people were hurt in the incident. The one fatality on board the train was the first on the Metrorail system since a crash between two trains in 2009 that killed eight passengers and a train operator.

NTSB officials think "an electrical arcing event" happened about 1,000 feet in front of the train and filled the tunnel the smoke, but they aren't sure.