New York -- A construction worker fell about 40 stories to his death Thursday at a Manhattan skyscraper being built by the developer of the World Trade Center, authorities said Thursday.

The man, who was a rigger on a crew dismantling a crane, fell either from the crane or a 20-foot, moveable walkway linking it to the glass-walled skyscraper, said Deputy Fire Chief Anthony DeVita.

The accident happened on W. 42nd St., where trade center developer Larry Silverstein is building two 60-story luxury apartment buildings.

Silverstein referred questions to the general contractor, Gotham Construction, which didn't return a message seeking comment.

More than 20 people have died in New York City construction accidents this year, including nine in two crane collapses. A window worker died last week after falling 12 stories from a Manhattan building.