The incident took place just before 11 a.m. outside Bronx-Lebanon Hospital on Grand Concourse and 173rd Street in the Highbridge section of the Bronx.
The worker - identified as 38-year-old Tristan Mananghaya, of Jersey City, - was taken to the hospital, where he was pronounced dead.
Witnesses say the worker was guiding the crane operator when he was hit by the 40-foot-long AC unit.
The accident is under investigation.
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