Flames from a wildfire loom up over a neighborhood in Santa Paula, Calfornia, on Monday, Dec. 4, 2017. Ventura County fire officials say the blaze broke out Monday east of Santa Paula, a city of 30,000 people about 60 miles northwest of downtown Los Angeles. Powerful winds are pushing the blaze west toward the city along Highway 150, which is shut down. (Megan Diskin/The Ventura County Star via AP)

An explosive brush fire raced through Southern California with ferocious speed, spreading from about 50 acres to an estimated 31,000 acres in a matter of hours, forcing thousands of residents to flee and leaving at least one person dead.

Named the Thomas Fire, it began in a canyon near Santa Paula, about 65 miles northwest of downtown Los Angeles. By 4 a.m. Pacific time, the fire had advanced into the city limits of Ventura, with a population of more than 100,000, emergency officials said.

“The fire is still out of control and structures continue to be threatened throughout the fire area,” officials said in a pre-dawn update. “Due to the intensity of the fire, crews are having trouble making access and there are multiple reports of structures on fire.”

The Ventura County Fire Department issued a dire warning early Tuesday, saying conditions were expected to worsen. “Incident commander reporting winds are increasing, expect fire behavior to increase over the entire incident,” a department spokesperson tweeted.

One person was killed in a car crash while trying to evacuate from the fires, Ventura County Fire Chief Mark Lorenzen said at an overnight news conference.

The fire has destroyed at least 150 structures, according to the department, which said at least one firefighter has been injured in the blaze.

Authorities have given evacuation notices to more than 27,000 residents in the cities of Santa Paula and Ventura, both of which have declared states of emergency. More than 7,500 homes are under mandatory evacuation, authorities said in a statement early Tuesday morning.

“The prospects for containment are not good,” Lorenzen said in a news conference, adding that there was no possibility of using aircraft at night to help contain the fire.

Four helicopters were making water drops to fight the fire but by 9:30 p.m. local time but were grounded after conditions were deemed unsafe for them to fly at night.

“It’s always difficult and somewhat dangerous to fly at night, so depending on different conditions and the geographic challenges is how they evaluate whether or not they can operate at night,” Ventura County firefighter Jason Hodge told the Los Angeles Times.

Choppers and fixed-wing aircraft “are expected to attack the fire at daybreak,” officials said in a statement.

The fire also caused outages throughout Santa Barbara and Ventura counties, leaving more than 260,000 people without power, Southern California Edison said in a tweet.

It began Monday in the hills near Thomas Aquinas College in Santa Paula, the Los Angeles Times reported. It was first reported at 6:24 p.m. Pacific Time, Ventura County Fire Sgt. Eric Buschow told The Washington Post, and has moved “unbelievably fast” since then.

A mixture of dry foliage from a sustained drought, low humidity and sustained winds of more than 30 miles per hour throughout the evening led to its explosive growth, according to Buschow. Some outlets reported the winds exceeded 50 miles per hour.

The National Weather Service issued a red flag warning for Ventura and Los Angeles, saying wind gusts between 50 and 70 miles per hour are likely through Thursday.