C.J. Franzitta, who works about five blocks away, said part of the crane was holding steel beams and appeared to let go. He said he heard a rumble and saw at least one giant steel beam fall.
The crane was about 40 stories up and the accident caused one floor to collapse into another, Franzitta said. The crane "seemed to be going at breakneck speed -- up and down, up and down," he said.
Trump's executive assistant, Rhona Graff, referred inquiries to the construction company, Bovis Lend Lease. A telephone call to Bovis wasn't immediately returned.
The 45-story building is scheduled to open in 2009.
City inspectors were investigating, spokeswoman Robin Brooks said.
