A worker died inside West End Towers, 75 West End, Friday morning, officials said. View Full Caption DNAinfo/Trevor Kapp

MANHATTAN — A mechanic was killed when an elevator three floors above him unexpectedly dropped inside an Upper West Side high-rise apartment building Friday morning, crushing him to death, the FDNY said.

The 30-year-old mechanic was working atop an elevator inside the West End Towers, at 75 West End Ave, about 11:20 a.m. when the incident occurent, FDNY deputy assistant chief Roger Sakowich said.

"We believe he was on top of the one car and the other one came down," Sakowich said. "The gentleman below got crushed by the elevator between the first floor and the basement."

The worker, whose name was not immediately released, was pronounced dead at the scene, officials said.

His partner, who was outside the elevator shaft at the time, was not injured.

It was not immediately clear why the elevator moved or what company the victim worked for.

Building tenants said they were shaken up to learn of the worker's death.

West End Towers, which offers two-bedroom aparments for $4,500, has three open violations from April 2014 for failure to maintain service equipment on the elevator, according to Department of Buildings records.

It was cited on April 4 for expired tags, unavailable documents and the botched installation of devices that ensure cables don't tangle and another that ensures doors don't open between floors, a DOB spokesman said.

It was cited again on April 21 because adjustments were needed on a lock mechanism and the malfunction of a device atop an elevator car meant to reduce its speed during inspections, the spokesman said. The malfunction prevented the elevator from descending.

It was not immediately clear if that contributed at all to the worker's death.

DOB officials were dispatched to the scene of Friday's incident.

Tenants in the building said they were shaken up by the tragedy.

"I just saw this huge collection of [emergency] vehicles and knew something awful had happened. This gentleman woke up this morning and he's not here now," said building resident Richard Fischer, 56.

"It's just the craziest thing," Fischer added.

Officials at the Brodsky Organization, which owns and manages the towers, did not immediately have any information about the incident.