Helicopter delivers HVAC unit to hotel in downtown San Francisco

SAN FRANCISCO (KGO) -- A low-flying helicopter was spotted near San Francisco's Union Square early Saturday morning.

It wasn't a movie shoot - but a lift job to hoist HVAC unit on and off the very top of the Hilton hotel.

The specially outfitted sky crane is called in for the most delicate jobs.

Twitter users posted video of the rare scene online, at first thinking it was a rescue operation or a film shoot.