Four bodies are found after an hours-long standoff. California Gov. Jerry Brown orders flags at the state capitol to be flown at half-staff.
The move is the most aggressive one yet in the federal push to force so-called sanctuary cities and states to cooperate with immigration authorities.
A three-day sweep across a large area comes after Oakland's mayor sounded an alert about the impending raids.
In another dry winter, one-fourth of the state's population is now under severe drought conditions, the U.S. Drought Monitor reports.
The California governor's visit comes as the U.S. orders the Russian consulate in San Francisco closed; Putin pens article on economic conference in China.
Cost concerns may derail efforts by lawmakers and advocates to require more frequent inspections and a swifter response to allegations of abuse and neglect.