California wildfires: 'We have found bodies intact, we have found ash and bone'
The confirmed death toll from several fires in the US state of California has climbed to 31, marking the state's deadliest week of wildfires in state history.
The grim record was reached as firefighters began to gain ground on Thursday (Friday NZ time) against the spread of the wildfires that prompted mass evacuations and left hundreds missing in the heart of California's wine country.
A brief resurgence of dry, gusty winds threatened to push flames into the Napa Valley town of Calistoga, whose 5000-plus residents were ordered from their homes on Wednesday night as conditions worsened and fire crept closer.
Calistoga Mayor Chris Canning said anyone refusing to heed the mandatory evacuation would be left to fend for themselves if fire approached, warning on Thursday: "You are on your own."
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Still, extreme wind conditions that had been forecast for Wednesday night and early Thursday failed to materialise, giving crews a chance to begin carving containment lines around the perimeter.
"Overall, we are definitely making progress," said Daniel Berlant, assistant deputy director of the California Department of Forestry and Fire Protection.
Nearly two dozen blazes spanning eight counties have raged largely unchecked since igniting on Sunday night, scorching more than 190,000 acres – an area nearly the size of New York City – and destroying at least 3500 homes and other buildings.
Entire neighbourhoods have been reduced to panoramas of ash, smouldering ruins, charred trees and burned-out cars by a series of firestorms that rank among the deadliest and most destructive in California's history.
The official cause of the disaster was under investigation, but power lines knocked down by gale-force winds may have sparked the conflagration.
Thirty-one people have been confirmed dead, and authorities said the death toll could climb higher.
Fire officials have said some of the victims were asleep when the fast-moving fires engulfed their homes before they could escape.
"We have found bodies that were completely intact, and we have found bodies that were no more than ash and bone," Sonoma County Sheriff Rob Giordano told reporters.
As many as 900 missing-persons reports had been filed in Sonoma County alone, although 437 have since turned up safe, Giordano said.
It remained unclear how many of the 463 still listed as unaccounted for might be actual fire victims rather than evacuees who failed to alert authorities after fleeing their homes, he said.
"The best we can pray for is that they haven't checked in," emergency operations spokeswoman Jennifer Larocque said.
The fiercest of the blazes, the so-called Tubbs fire, accounted for 14 of the fatalities, all in Sonoma County, making it the deadliest single blaze since 2003, according to state data.
About 25,000 people remained displaced on Wednesday as the fires belched smoke that drifted over the San Francisco Bay area, about 80 kilometres to the south, where visibility was shrouded in haze and vehicles were coated with ash.
The National Weather Service warned on Thursday morning of persistent "critical fire weather conditions" in the fire zone for the next three days, with no rain expected and dry winds from the north with gusts upward of 55kmh.
The Tubbs fire on Thursday was within 3km of Calistoga, which had appeared to be in the path of advancing flames but was spared on the first night of the fires.
Whether the town burns "is going to depend on the wind", Calistoga's Fire Chief Steve Campbell said early on Thursday. "High winds are predicted but we have not received them yet."
New evacuations also were issued in Sonoma County late on Wednesday for parts of Santa Rosa, the largest city in the wine-producing region, and Geyserville, a town of 800 people.
While the cause of the fires have not been determined, they are thought to have been sparked by power lines toppled by gale-force winds and fanned by arid winds that blew into Northern California toward the Pacific on Sunday night.
Wildfires have damaged or demolished at least 13 Napa Valley wineries, a vintners' trade group said on Tuesday.
The confirmed death toll from the spate of fires stood at one more than the 25 lives lost when a firestorm swept the Oakland Hills in October 1991.
In addition to high winds, the fires have been stoked by an abundance of thick brush left ready to burn by a dry, hot summer.
California Governor Jerry Brown has declared a state of emergency in several northern counties, as well as in Orange County in Southern California, where a fire in Anaheim destroyed 15 structures and damaged 12 earlier in the week.