Sinkhole shuts down Alvarado Boulevard in Union City

Crews are working to determine what caused a large sinkhole at a major Union City intersection Wednesday afternoon, city officials said.

Alvarado Middle School parents were being asked to drop their children off behind the campus on Fredi Street, instead of on Alvarado Boulevard Thursday morning as crews worked on repairing the road. The sides of the hole – originally about 10 by 12 feet but now excavated to 25 by 25 feet – must be shorn up before crews can access the water main and complete the fix work, city spokeswoman Lauren Sugayan said. It has caused no injuries or damage, according to Union City Police Detective Brian Baumgartner.

Crews from the Alameda County Water District, which supplies water to about 340,000 Tri-City residents, repaired the main and restored service to customers by 11 a.m. Thursday, district spokeswoman Sharene Gonzales said.

The road is closed as crews try to figure out how the sinkhole formed and patch the road.

KTVU-TV reported that the roughly 12-by-10-foot sinkhole at Alvarado Boulevard and New Haven Street was first reported Wednesday afternoon. For now, those who live in the area are relying on a temporary “water” system so water service hasn’t been disrupted.

It is unclear what caused the sinkhole and the roadway remains closed.

Once the water line is fixed, the Union Sanitary District will inspect the sewage pipe line beneath it. City officials estimate the road won’t be open until late Tuesday at the earliest.