NEW YORK (AP) — Authorities say a mechanic has been crushed to death while working in an elevator shaft in a New York City residential tower.

Police say the 30-year-old man was fatally injured at around 11:30 a.m. Friday in a building on Manhattan's Upper West Side.

A deputy assistant fire chief, Roger Sakowich, tells The Wall Street Journal that the empty elevator moved down three floors, injuring the man who was working below it. He says it isn't clear whether the elevator fell.

A second mechanic wasn't injured.

The city's buildings department is investigating.