Police in Seattle are searching for a gunman who opened fire at a light-rail station late Friday night, killing one and injuring two others, authorities said. The shooting broke out in the city's downtown area around 9:30 p.m. local time, CBS affiliate KOIN-TV reported.

First responders discovered three victims underground at the Westlake Station. Medics performed life-saving measures on one of the victims who died, the Seattle Fire Department said.

"As I get down into the tunnel, on the bottom escalators, there's a guy sitting there, bleeding out from his leg," witness David Lewis told KOIN-TV.

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Lewis said the victim warned him not to enter the station because the gunman was nearby.

Investigators believe the shooting began above ground at a nearby McDonald's. They believe only one suspect is responsible. An investigation is ongoing.