SONOMA, Calif. — Search-and-rescue teams, some with cadaver dogs, started looking for bodies Thursday in parts of California wine country devastated by wildfires, an indication that more dead were almost sure to emerge from the charred ruins of communities consumed by the flames.
At least 27 people have died and at least 3,500 homes and businesses have been destroyed by the blazes, which could become the deadliest and most destructive in California history.
Sonoma County Sheriff Robert Giordano said officials were still investigating hundreds of reports of missing people and that recovery teams would soon begin conducting "targeted searches" for specific residents at their last known addresses.
"We have found bodies almost completely intact, and we have found bodies that were nothing more than ash and bones," the sheriff said.
Some remains have been identified using medical devices that turned up in the scorched heaps that were once homes. Metal implants, such as artificial hips, have ID numbers that helped identify the person, he said.
Winds up to 45 mph (72 kph) were expected Thursday in areas north of San Francisco, and stronger, more erratic gusts were forecast for Friday. Those conditions could erase modest gains made by firefighters.
"We are not out of this emergency. We are not even close to being out of this emergency," Emergency Operations Director Mark Ghilarducci told a news conference Thursday.
More than 8,000 firefighters were battling the blazes, and more manpower and equipment was pouring in from across the country and from as far as Australia and Canada, officials said.
The ferocious fires that started Sunday leveled entire neighborhoods in parts of Sonoma and Napa counties. In anticipation of the next round of flames, entire cities evacuated, leaving their streets empty, the only motion coming from ashes falling like snowflakes.
Fire officials are investigating whether downed power lines or other utility failures could have sparked the fires. It's unclear if downed lines and live wires resulted from the fires or started them, said Janet Upton, a spokeswoman for the California Department of Forestry and Fire Protection.
An estimated 25,000 people have been driven from their homes by the flames, including the entire community of Calistoga, a historic resort town known for wine tastings and hot springs with a population of 5,300. A few residents left behind cookies for firefighters with signs reading, "Please save our home!"
As the wildfires raged for a fourth day, they continued to grow in size. A total count of 22 fires on Wednesday grew to 21 on Thursday because two large fires had merged together, said state Fire Chief Ken Pimlott.
Many burned out of control. The flames spanned more than 300 square miles (777 square kilometers), an area equivalent to the size of New York City's five boroughs.
Fire crews reported some progress on a blaze burning in Napa and Sonoma Counties, the heart of wine country, bringing containment to 10 percent.
The ash rained down on Sonoma Valley, covering windshields, as winds picked up. Countless emergency vehicles hurried toward the flames, sirens blaring, as evacuees sped away after jamming possessions into their cars and filling their gas tanks.
Helicopters and air tankers assisted thousands of firefighters who were trying to beat back the flames. Until now, the efforts have focused lives and safety rather than extinguishing the blazes, partly because the flames were shifting with the wind and targeting communities without warning.
Gecker reported from San Francisco. Associated Press writers Olga R. Rodriguez, Andrew Dalton and Juliet Williams Dalton in San Francisco contributed to this report.