A crane accident at a Donald Trump hotel-condominium tower under construction in Manhattan's trendy SoHo neighborhood sent a worker plummeting 40 stories to his death and injured three other people, authorities said.

The worker's identity was not immediately released. The three injured were taken to a hospital, two with serious injuries, one with minor injuries, fire department officials said.

Construction is being overseen by Bovis Lend Lease, the main contractor handling the dismantling of a former bank building across from the site of the Sept. 11, 2001, attacks that caught fire in August, killing two firefighters.

A witness, C.J. Franzitta, said he saw Monday's accident from his office window. Part of the crane was holding steel beams and appeared to let go, he said.

Franzitta said the crane was about 40 stories up, and the accident caused one floor to collapse into another.

The crane "seemed to be going at breakneck speed -- up and down, up and down," he said.

Inspectors from the city's Department of Buildings were at the scene investigating, spokeswoman Robin Brooks said.

The Trump site was cited for two high-risk violations Oct. 26, one for operating a crane in an unsafe manner and the other for failing to safeguard public property affected by construction operation, said Manhattan Borough President Scott Stringer.

"Why are we allowing this crane to operate when there's been no resolution to this violation?" Stringer said. "I find that very troubling."

Trump's executive assistant, Rhona Graff, referred inquiries about the accident to Bovis Lend Lease, which is also handling including the Sept. 11 memorial and a transit hub at ground zero.

Bovis spokeswoman Mary Costello released a statement saying the company was conducting its own investigation while working with local authorities to determine the cause.

"Our hearts go out to the family of the deceased concrete worker, and our prayers are with the injured workers," the statement said.