Unstable piece of heavy equipment closes part of San Francisco street as precautionary measure

An unstable piece of heavy equipment in San Francisco's tenderloin diverted traffic for hours this afternoon.

Swinerton Builders worked for hours here to shore up that site, before giving KTVU the word that the crane is in no danger of collapse.

"This afternoon we encountered an unforeseen site condition on the job site, and as a precautionary measure we contacted the SFMTA to close down this street area," said Lori Dunn from Swinerton Builders.

Golden Gate between Taylor and Leavenworth Streets was shut down for about two hours as crews worked to stabilize what they called a void, or a soft spot in the soil, under the drilling rig which was working at the corner of Jones Street and Golden Gate Avenue.

Swinerton builders tells KTVU that work halted when crews encountered the problem, and that crews began using cement to try to fill that soft spot.

The builder says they contacted the city to shut down traffic out of an abundance of caution.

"We were concerned about some potential tipping, that’s why we closed the street, but again we believe everything is stabilized at this point," said Dunn.

Swinerton tells KTVU the company has been working at this site since January on what will eventually be new housing.