Two of California’s fastest-burning wildfires in decades overtook several Northern California towns.

An explosive wildfire burned largely unchecked Monday after incinerating hundreds of homes and other buildings throughout rural communities north of California’s Napa Valley, leaving at least one person dead and sending tens of thousands fleeing down flame-lined streets.

The fire and another in the Gold Rush country of the Sierra Nevada foothills, about 120 miles (193 kilometers) to the southeast, are the worst of a dozen burning in the state. Between them, they have destroyed at least 720 homes and hundreds of other structures and displaced 23,000 people, fire officials said.

Cooler weather Monday provided some relief to the crews who gained 10 percent containment on the fire that marauded through Middletown and other parts of rural Lake County, less than 100 miles (160 kilometers) north of San Francisco.

A 72-year-old disabled woman who was trapped in her home died over the weekend in the wildfire about 20 miles (30 kilometers) outside the famed Napa Valley. Others are missing, but officials don’t yet know whether those unaccounted for are elsewhere.

“These fires will take lives and they will cause injuries, and we have to do the best we can, because we are really in a battle with nature, that nature is more powerful than we are,” Brown said.

Authorities flooded with requests for evacuation assistance could not rescue the disabled woman who called for help Saturday evening. The flames prevented deputies from reaching her subdivision, and rescue workers found her body when the fire subsided, Lake County Sheriff’s Lt. Steve Brooks said.

The victim was identified by her family as retired teacher Barbara McWilliams, 72. McWilliams had settled in the Middletown area in the last year, her family said. Her caretaker, Jennifer Hittson, told the Santa Rosa Press Democrat newspaper that McWilliams had advanced multiple sclerosis and had major physical disabilities that limited her ability to walk.

The fire exploded in size within hours as it chewed through brush and trees parched from four years of drought, destroying 400 homes, two apartment complexes and 10 businesses since igniting Saturday, Cal Fire spokeswoman Lynn Valentine said. By Monday morning, crews had gained 5 percent containment of the 95-square-mile (250-sq. kilometer) blaze.

Residents fled from Middletown, a town of more than 1,000 residents, dodging smoldering telephone poles, downed power lines and fallen trees as they drove through billowing smoke. Several hundred people spent Sunday night at the Napa County Fairgrounds and awoke to a breakfast of eggs, bacon, and doughnuts.

Four firefighters who are members of a helicopter crew suffered second-degree burns during the initial attack on the fire. They remained hospitalized in stable condition.

Gov. Jerry Brown on Sunday declared a state of emergency to free up resources. He had already declared a state of emergency for the separate 111-square-mile (290-sq. kilometer) wildfire southeast of Sacramento that has turned the grassy, tree-studded Sierra Nevada foothills an eerie white.

Ghilarducci, of the Governor’s Office of Emergency Services, said this summer’s fires are the most volatile he has seen in 30 years of emergency response work. The main cause behind the fast-spreading fires is dry conditions from the drought.

Firefighters have maintained a precautionary line around Grant Grove, an ancient grove of Giant Sequoia trees, and set prescribed burns to keep the flames from overrunning it. The grove is named for the towering General Grant tree that stands 268 feet (81 meters) tall.