An huge industrial air conditioning unit fell roughly 40 feet onto a downtown Oakland Street from a helicopter Saturday morning.

The incident, which shook Clay Street near 14th Street, occurred at about 10:15 a.m. when cables lifting the cooling tower broke as the helicopter was rising, sending the metal equipment, roughly the size of a truck, slamming into the middle of what would normally be a busy downtown street and sending construction workers running for cover.

There were apparently no injuries.

“By the time we got there, this helicopter had just arrived,” said Rudi Tcruz, an eyewitness. “It picked up the air conditioning unit, and then the cables snapped. The helicopter is so loud that when it hit the ground you couldn’t even hear the impact.”

Tcruz, a freelance graphic artist who lives in Oakland nearby, had gone for a walk with his brother, Gabriel Tcruz, to watch the construction work and take photos. In recent days, the Sikorsky Sky Crane helicopter has been lifting air conditioning units and other equipment onto the roof of nearby buildings, drawing the attention of local residents.

“You could definitely see the dismay,” he said of the construction workers. “One of the guys, as it crashed, turned around and ripped off his helmet.”

The accident occurred near the Elihu M. Harris State Office Building, near Oakland City Hall. The street was closed to traffic during the work. Oakland Police and city officials had not returned calls Saturday night seeking more details.

After the accident, Tcruz said he and his brother left the area, then returned about an hour later to see the heavily damaged air conditioning unit, made by Baltimore Air Coil, a company based in Madera, near Fresno, being loaded onto the back of a large flatbed truck. Videos show that Sikorsky helicopter, which can lift up to 25,000 pounds, did not have its flight stability altered when the huge weight fell. It continued to hover over the street.

“Luckily it didn’t seem like anybody got injured,” Tcruz said. “But there were some construction workers who were pretty close to it. It was lucky for those guys that they didn’t get hit by flying metal. With so much construction goin on in downtown Oakland, it’s a good reminder to people to be aware of your surroundings.”