A water main break in Castro Valley damaged several homes this evening and caused a large sinkhole, a utility spokeswoman said.
The break was reported just before 7 p.m. near the corner of Seven Hills Road and Santa Maria Avenue, an Alameda County fire dispatcher said.
The break was at a top of a hill and flowed down into several houses causing water damage, the dispatcher said.
East Bay Municipal Utility District crews were working to shut down the flow of water and had stopped most of it by about 9:40 p.m., East Bay MUD spokeswoman Andrea Pook said.
A 10-foot by 15-foot sinkhole opened in the break, and two wheels of a fire truck became fell in, Pook said.
Pook said it is not yet clear how many houses have lost water service.
Fire and East Bay Municipal Utility District crews remain there tonight. The streets in the neighborhood remain shut down as crews assess the damaged houses.