At least 10 people were killed and thousands of structures were burned as fierce wildfires raged in the Los Angeles area, officials said. Fast-moving flames blazed through homes and businesses as residents fled smoke-filled canyons and picturesque neighborhoods that are home to many celebrities.

Many of the towering fires that began Tuesday were fueled by powerful Santa Ana winds, which gusted to more than 70 mph (112 kph) in some spots. The winds dropped Thursday, but the National Weather Service warned that even the reduced gusts could still spread fire rapidly and the wind is expected to strengthen again Thursday evening. Another round of strong winds may form Tuesday.

The exact death toll remained unclear, but it was expected to rise as crews begin to search the rubble.

Gov. Gavin Newsom said California has deployed more than 1,400 firefighting personnel to battle the blazes. Oregon, Washington, Utah, New Mexico and Arizona dispatched teams to assist.

AccuWeather, a private company that provides data on weather and its impact, increased its estimate of the damage and economic loss to $135 billion to $150 billion. Government officials have not yet released any damage estimates.

Here’s what to know about the fires:

The Palisades Fire is the most destructive in LA history

More than 5,300 structures have been damaged or destroyed in the hilly coastal neighborhood of Pacific Palisades, making it the most destructive fire in Los Angeles history. Dozens of blocks were flattened to smoldering rubble, with only the outlines of homes and their chimneys left.

The wreckage surpassed that of the Sayre Fire of November 2008, which destroyed 604 structures in Sylmar, the northernmost suburb of the city, according to statistics kept by the Wildfire Alliance, a partnership between the city’s fire department and MySafe:LA.

Over 30 square miles (77 square kilometers) burned in Pacific Palisades, which is dotted with celebrity homes and was memorialized by the Beach Boys in their 1960s hit “Surfin’ USA.” The flames torched iconic landmarks including part of Palisades Charter High School, which has been featured in many Hollywood productions, including the 1976 horror movie “Carrie” and the TV series “Teen Wolf.” Actor Billy Crystal and his wife Janice lost their home of 45 years.

Other fires are also causing havoc

Farther inland, the Eaton Fire north of Pasadena burned more than 5,000 structures, which includes homes, apartment or commercial buildings and vehicles. It also substantially damaged five school campuses in Altadena and scorched more than 21 square miles (54 square kilometers).

Employees at a senior center pushed dozens of residents in wheelchairs and hospital beds to a parking lot to escape.

The Los Angeles Fire Department issued evacuation orders Thursday afternoon for a new blaze, named the Kenneth Fire, which broke out near West Hills, a neighborhood densely packed with homes in the San Fernando Valley about 11 miles (18 kilometers) northwest of Pacific Palisades. It ballooned in size, charring more than 1 square mile (2.6 kilometers) within hours of igniting, and forced evacuations.

The Hurst Fire, which started Tuesday night, prompted evacuations in Sylmar in the San Fernando Valley.

And in the Hollywood Hills, the Sunset Fire broke out Wednesday evening and burned near the Hollywood Bowl and other iconic landmarks. Firefighters were able to manage the flames, and evacuation orders were lifted Thursday morning.

Altogether the fires have consumed about 55 square miles (142 square kilometers) — larger than the size of San Francisco.

Biden approves additional funding

President Joe Biden said during a White House briefing with staff Thursday that he was making federal resources available and approved additional funding to help California battle the fires, saying they were the “worst fires to ever hit Los Angeles. Ever.”

The new funding will cover 100% of the cost for 180 days for hazardous materials removal, temporary shelters, first responder salaries and measures to protect life, he said.

Biden said he was not in a position to answer whether California would continue to receive federal funding to help combat the fires after President-elect Donald Trump takes office Jan. 20. “I pray to God they will,” Biden said.

Thousands have been ordered to evacuate

Nearly 180,000 people were under evacuation orders Thursday.

The flames threatened highly populated and affluent neighborhoods, including Calabasas and Santa Monica, home to California’s rich and famous. Hollywood stars including Mark Hamill, Mandy Moore and James Woods were among those forced to flee, and Moore later said she lost her home in Altadena.

Bad air quality is affecting millions

A thick cloud of smoke and ash filled the skies, prompting air and dust advisories for 17 million people across a vast stretch of Southern California, according to the South Coast Air Quality Management District.

The worst conditions were in the vicinity of the fires. In East Los Angeles, the air quality index hit an unhealthy 173. Good air quality is considered to be 50 or less.

Dr. Puneet Gupta, the assistant medical director for the Los Angeles County Fire Department, said wildfire smoke can cause heart attacks and worsen asthma, while burning homes can release cyanide and carbon dioxide.

Several events have been canceled and postponed

The Critics Choice Awards rescheduled Sunday ceremonies in Santa Monica for Jan. 26.

The organization that puts on the Oscars extended the voting window for Academy Award nominations and delayed next week’s planned nominations announcement.

Film studios canceled two movie premieres.

The Universal Studios Hollywood theme park closed for the day, but Disneyland, which is farther from the fires in Anaheim, remained open.

Universal Studios also canceled shooting for numerous series, including “Hacks,” “Ted Lasso” and “Suits LA.”

All schools were closed Thursday and were to remain closed Friday in the Los Angeles Unified School District.

The NFL has moved the Los Angeles Rams’ wild-card playoff game against the Minnesota Vikings to Arizona because of the fires. The game will be played Monday night at the home of the Arizona Cardinals in suburban Glendale, Arizona.

The NBA postponed the Lakers’ game against the Hornets, and the NFL said it is monitoring conditions to determine if Monday’s playoff game between the Los Angeles Rams and Minnesota Vikings will be affected.

Many people are without power and water

More than 285,000 customers were without electricity in Southern California, nearly half of them in Los Angeles County, according to PowerOutage.us, which tracks outages nationwide.

Sewer, water and power infrastructure across the region has been significantly damaged, officials said.

Authorities warn looters

Looters who take advantage of the wildfire crisis by targeting vulnerable communities will be prosecuted, officials promised. There have been at least 20 arrests.

“This is simply unacceptable,” Los Angeles County Board of Supervisors Chair Kathryn Barger said. “I promise you, you will be held accountable.”

Officials planned to implement a curfew around the two main fires as early as Thursday evening, and National Guard members were expected to be stationed near burn areas.

Powerful Santa Ana winds that fueled catastrophic Los Angeles wildfires expected to return in days