A woman was killed when she jumped in front of a train at the 59th Street station in Manhattan on Monday afternoon, police sources said.

The northbound No. 5 train was pulling into the station when the suicidal woman leaped shortly before 2 p.m., sources said. She was declared dead at the scene, said MTA officials.

The incident was causing severe delays on the Lexington Avenue line, with No. 4 and 5 trains running locally from 42nd Street to 125th Street as cops investigated.