At least 10 people died in a number of wildfires in Northern California in the United States on Monday. Authorities said 14 wildfires broke out simultaneously across eight counties and spread rapidly, destroying over a thousand homes, businesses and other structures, the Los Angeles Times reported.

The fires have gutted 73,000 acres of land and forced over 20,000 people to evacuate. Thousands of firefighters are battling the blaze amid strong winds that are fanning the flames, said CalFire Spokesperson Daniel Berlant, according to Reuters.

California Governor Jerry Brown has declared a state of emergency for Napa, Sonoma and Yuba counties in the north, which make up some of the state’s main wine-manufacturing regions, as well as in Butte, Lake, Mendocino and Nevada. He extended the state of emergency to the Orange County in the south where another fire erupted.

“Late last night, starting around 10 o’clock, you had 50 to 60 mph winds that surfaced – really across the whole northern half of the state,” said California Fire Director Ken Pimlott. “Every spark is going to ignite.”

Authorities in San Francisco were forced to issue an air quality alert as the winds brought smoke from the fires to South California.

The state witnesses wildfires at the end of the dry season in October because of high winds, low humidity and dried-up vegetation. The drought in California made the situation worse.