Wildfires threatening Los Angeles have killed at least 10 people and devoured nearly 10,000 structures, with five fires burning into a third night on Thursday, as dry desert winds fanning the flames again gathered strength.

The Palisades Fire between Santa Monica and Malibu on the city’s western flank and the Eaton Fire in the east near Pasadena already rank as the most destructive in Los Angeles history, consuming more than 34,000 acres (13,750 hectares) – or some 53 square miles – turning entire neighborhoods to ash.

The death toll from the blazes rose to 10, Los Angeles County’s Medical Examiner said in an update late on Thursday, without providing identities or other details.

Los Angeles County Sheriff Robert Luna told an earlier news conference that he expected the number to grow.

“It looks like an atomic bomb dropped in these areas.

“I don’t expect good news, and we’re not looking forward to those numbers,” Luna said.

Private forecaster AccuWeather estimated the damage and economic loss at between $135 billion and $150 billion, portending an arduous recovery and soaring homeowners’ insurance costs.

Southern California Edison said on Thursday it had received notices from insurance companies to preserve evidence related to the Eaton Fire, but said no fire agencies have pointed to the utility’s connection to the fire.

“We’re already looking ahead to rebuild the city of Los Angeles aggressively,” said Mayor Karen Bass, a Democrat, who faced criticism from President-elect Donald Trump and other Republicans over her handling of the disaster.

President Joe Biden, who declared a major disaster on Tuesday, promised on Thursday that the federal government would reimburse 100 per cent of the recovery for the next 180 days to pay for debris and hazard material removal, temporary shelters, and first responder salaries.

“I told the governor and local officials to spare no expense to do what they need to do and contain these fires,” Biden said after meeting with senior advisers at the White House.

In all, five wildfires burned in Los Angeles County, with the largest Palisades fire just 6 per cent contained and the Eaton fire 0 per cent contained.

Skies buzzed with aircraft dropping retardant and water on the flaming hills.

A large Super Scooper aircraft on loan from Canada was damaged and grounded after hitting an unauthorised civilian drone near the Palisades fire, the L.A. County Fire Department said.

There were no injuries.

One rapidly growing blaze broke out on Thursday near Calabasas, one of the wealthiest cities in the U.S. and home to numerous celebrities and gated communities.

The so-called Kenneth Fire expanded to 960 acres (388 hectares) in a matter of hours.

With nerves on edge, Los Angeles County mistakenly sent an evacuation notice countywide to a population of 9.6 million, even though it had been meant only for the area of the Kenneth Fire, officials said.

A correction was quickly sent.

Officials said the Eaton Fire had damaged or destroyed 4,000 to 5,000 structures while the Palisades Fire destroyed or damaged another 5,300 structures.

Some Pacific Palisades residents ventured back to areas the fire had already swept through, where brick chimneys were left looming over charred waste and burnt-out vehicles.

“We are alive. That’s all that matters,” private security guard Bilal Tukhi said while standing watch outside his employer’s damaged home, saying the scene reminded him of his native, war-torn Afghanistan.

School was canceled for a second day on Friday due to the contaminated air, Superintendent Alberto Carvalho said.

Winds dropped on Thursday from the 100-mile-per-hour (160-kph) gusts seen earlier in the week, permitting crucial aerial support for crews on the ground.

However, officials said winds intensified again overnight, and red flag conditions were expected until Friday afternoon.

In Altadena, a racially and economically diverse community nearby, many residents told Reuters they were concerned government resources would be channeled towards high-profile areas popular with A-Listers, while insurance companies might shortchange less affluent households that don’t have the financial means to contest fire claims.

“They’re not going to give you the value of your house … if they do you really have to fight for it,” said Kay Young, 63, her eyes welling up with tears as she stared at a sprawl of smoking rubble, the remnants of a home that had been in her family for generations.

Firefighting crews managed to fully control the Sunset Fire in the Hollywood Hills, after flames had raged atop the ridge overlooking Hollywood Boulevard’s Walk of Fame on Wednesday night.

In Pacific Palisades, once-palatial homes stood in ruins, while downed power lines and abandoned cars littered the roadways.

One resident, John Carr, 65, said he defied evacuation orders and stayed to successfully protect his home.

“The house was built by my mother and father in 1960 and I lived here my whole life so there’s a lot of memories here.

“And I think I owed it to them as well to try my best to save it.”

Carr said there were no fire crews to help him try to save his neighbors’ homes.

“If they had had some fire trucks and just put a squirt here, a squirt there, and kept an eye on things, all these houses would be here now.”

Officials said they were working to establish curfews for areas affected by mandatory evacuation orders.

Aerial video showed block after block of leveled homes, just as satellite images showed the two largest fires forming a pincer around the city and thick plumes of smoke from the fires being blown out over the Pacific Ocean.

The homes of movie stars and celebrities were among those consumed by flames.

Chef Jose Andres, the Spaniard, known for providing free food to disaster victims around the world set up a food truck near the Palisades Fire on Pacific Coast Highway.

“Everybody needs support and love in these moments, wealthy or not, poor or not,” he said.

On Thursday Actor Jamie Lee Curtis said her family would donate $1 million to relief efforts.

Firefighters from half a dozen other U.S. states and Canada were being rushed to California, in addition to U.S. federal personnel and materiel.

“To our American neighbors: Canada’s here to help,” said Canadian Prime Minister Justin Trudeau, whose country has experienced severe wildfires.