OAKLAND (CBS SF) — Crews are working Friday morning to repair a major water main break in Oakland’s Dimond neighborhood that has closed a freeway on-ramp and street and created a huge sinkhole, according to an East Bay MUD.

The 16-inch cast iron pipe ruptured sometime before 8 a.m. and sent water spilling down Montana Street near Dimond Avenue, just east of Interstate Highway 580, EBMUD spokeswoman Andrea Pook said. The pipe was installed in 1932, according to Pook.

READ MORE: Shoppers Welcome Heighten Police Presence In Downtown Walnut Creek

The westbound ramp of I-580 at Montana Street and Dimond Avenue were closed as crews attempted repairs on the water main and the large sinkhole that opened up on Dimond.

As of about 11 a.m., 12 customers including two apartment buildings were without water, but EBMUD said they were uncertain how many other homes in the area might be affected.

There were some reports of property damage including damage to homes and vehicles that were partially submerged during the initial break in the neighborhood. However, the extent of that damage was unclear, Pook said.

READ MORE: Police Officers Denied Service At San Francisco Restaurant Triggering Social Media Debate

“We don’t know when the break itself occurred, but it caused the sinkhole,” said Pook. “As you can see, it caused a lot of buckling this morning. There have been reports of property damage.”

Neighbors told KPIX 5 another water main break happened several months ago about a block away, but the damage was not nearly as bad.

East Bay MUD officials estimated that the repairs would not be completed until 9 p.m. Friday at the earliest.

MORE NEWS: Long Lines Form Outside San Mateo Event Center COVID-19 Vaccination Site

TM and © Copyright 2016 CBS Radio Inc. and its relevant subsidiaries. CBS RADIO and EYE Logo TM and Copyright 2016 CBS Broadcasting Inc. Used under license. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed. Bay City News Service contributed to this report.