SANTA ROSA, Calif. (Reuters) – Firefighters on Tuesday battled 17 wildfires that have killed at least 13 people and destroyed hundreds of buildings in Northern California’s wine country, as a drop in winds and cool fog gave them a chance to make progress in controlling the blazes.

About 1,500 homes and commercial buildings were destroyed statewide as flames spread across more than 115,000 acres (46,500 hectares) since Sunday, the California Department of Forestry and Fire Protection said in a statement.

North of San Francisco, the fires reduced houses to ashes in several communities. The city of Santa Rosa was particularly hard hit, with flames damaging a Hilton hotel and destroying a mobile home park.

The fires were fanned by high temperatures and dry conditions, which displaced tens of thousands of residents and forced schools and at least two hospitals in Sonoma County to close.

Steve Crawford, an operations chief for the California Department of Forestry and Fire Protection, said at a briefing for law enforcement and utility officials on Tuesday morning that a change in the weather could help firefighters.

“We need to jump on it and take advantage of this lull before any other wind jumps up,” he said. “There’s a lot of devastation out there, people running around who just lost everything.”

In the celebrated wine country north of San Francisco, Sonoma County bore the brunt of the fatalities with the sheriff’s department confirming seven fire-related deaths. Fires killed a total of 13 people statewide, according to state fire officials.

The status of the grape crop currently being harvested in Napa and Sonoma, where the largest fires burned, was unclear.

In addition to potential damage to vineyards from fire itself, sustained exposure to heavy smoke can taint unpicked grapes, according to wine-making experts.

More than 91,000 homes and businesses served by Pacific Gas & Electric were without power, with most of those customers in Northern California’s Sonoma and Napa counties, and gas was shut off to 28,000 customers, representatives for the utility company said.

California Governor Jerry Brown declared a state of emergency in Napa, Sonoma and five other counties. That included Orange County in Southern California, where a wildfire on Monday destroyed at least a half dozen homes in the affluent Anaheim Hills neighborhood, forcing the evacuation of thousands of residents, authorities said.

The Federal Emergency Management Agency has approved grants to help cover the cost of fighting 10 fires across the state, it said on Tuesday, without specifying the amounts.