Three residents of a 16-unit apartment complex were rescued by King County Fire District 20 firefighters following a two-alarm fire Sunday morning at the Greentree Apartments in Skway.

One of those injured was taken to Harborview Medical Center with life-threatening injuries.

Firefighters arrived at the complex in the 6900 block of South 123rd Street to find heavy smoke coming from a second-floor apartment and called a second alarm while rescuing two residents who were trapped on the third floor, according to Dave Nelson, a spokesman for the fire district.

One resident was rescued with a ladder and the other was assisted down the stairs, according to Nelson. During a search of the other units, firefighters found a male victim who had been injured in the fire.

King County Medic One transported the man to Harborview Medical Center in Seattle with life-threatening injuries. His condition at the hospital is unknown.

The fire is still under investigation by the King County Sheriff’s Arson and Fire Investigation Unit; no damage estimate is available at this time.

The Seattle chapter of the American Red Cross is assisting residents.