SANTA ROSA, Calif. (Reuters) – Thousands more Californians evacuated their homes on Saturday as fierce wildfires spread due to constantly shifting winds, and officials expected the official death toll of 35 from the week of fires to rise with hundreds of people still missing.

Sixteen major wildfires, some encompassing several smaller merged blazes, have consumed nearly 214,000 acres (86,000 hectares), roughly 334 square miles, an area larger than New York City.

The 35 confirmed fatalities – including 19 in Sonoma County – make this the deadliest fire event in California history. Some 100,000 people have been forced from their homes, including another 3,000 evacuated from the city of Santa Rosa, about 50 miles (80 km) north of San Francisco, and another 250 from nearby Sonoma city.

“It’s an unwieldy beast right now,” fire information officer Dennis Rein said at the Sonoma County Fairgrounds in Santa Rosa, the main staging area for the so-called Nuns Fire in Sonoma County, a wine-producing region.

More than 10,000 firefighters are battling the fires, which have destroyed 5,700 buildings and thrown California’s wine-producing industry, and related tourism, into disarray, damaging or destroying at least a dozen Napa Valley wineries.

Ground crews gained on the wildfires on Friday but drier weather and fast-changing winds complicated efforts on Saturday, sparking a new large wildfire in Lake County, officials said.

The Nuns Fire, which had killed at least one person, was only 10 percent contained with winds threatening more residential areas, Cal Fire spokesman Antonio Negrete said.

But the more deadly Tubbs Fire, which killed at least 17 people in Sonoma County, was 44 percent contained, which officials considered a victory.

“It’s cautious optimism but it’s optimism,” Negrete said of the Tubbs Fire.

Cal Fire had estimated the fires would be contained by Oct. 20 but may need to revise that date because of the winds that kicked up, Rein said.

“It’ll set us back a planning cycle. Everything is very dynamic,” Rein said.

The Nuns Fire forced evacuations north of Highway 12, which runs west-to-east from Santa Rosa inland.“Unfortunately, due to the wind conditions and the type of topography and fuels, those winds and topography are causing that fire to be very erratic, going in several different directions. The winds constantly change direction in that area,” Scott McLean, a fire captain with the California Department of Forestry and Fire Protection (Cal Fire), told CNN.

The Nuns burned some 300 acres (120 hectares) near Sonoma, damaging some buildings on the outskirts of the city, McLean said.

Numerous ground-based strike teams barreled down Highway 12 toward the fire early Saturday and 20 of the 70 helicopters available throughout the state were concentrated on the Nuns Fire, McLean said.

Air tankers from one air base dropped a record 330,000 gallons (1.2 million liters) of retardant on the fire on Friday, he said.

Whole neighborhoods of Santa Rosa have been reduced to landscapes of gray ash, smoldering debris and burned-out vehicles.

Some victims were asleep when flames engulfed their homes, and many survivors had only minutes to flee.

The fires’ death toll surpassed the 29 deaths from the Griffith Park fire of 1933 in Los Angeles.

With 235 people still missing on Saturday in Sonoma County alone, and rubble from thousands of incinerated dwellings yet to be searched, authorities have said the number of fatalities from the North Bay fires would likely climb.

The picturesque town of Calistoga, at the northern end of Napa Valley, faced one of the biggest remaining hazards. Its 5,000-plus residents were ordered from their homes on Wednesday night as a fierce blaze dubbed the Tubbs Fire crept to within 2 miles (3.2 km) of city limits.

The year’s wildfire season is one of the worst in history in the United States, with nearly 8.6 million acres (3.5 million hectares) burned, just behind 2012, according to the National Interagency Fire Center.