CALABASAS, CA - Water-dropping helicopters and hundreds of firefighters are battling a blaze in Los Angeles County that has forced the evacuation of at least 5,000 people, according to authorities.
The wildfire, which broke out Saturday afternoon, has burned about 500 acres in and around Calabasas -- a relatively affluent area which is home to a handful of celebrities, including Jessica Simpson and Toni Braxton, authorities said.
"This fire has a long way to go before firefighters can actually contain [it]," CNN Meteorologist Derek Van Dam said.
More wind will help bring up humidity from the coast, Van Dam said, which will help firefighters.
About 5,000 residents have been evacuated so far, the majority of which faced mandatory evacuations, according Deputy Jeffrey A. Gordon with the Los Angeles Sheriff's Department.
Evacuated residents are being urged to go to nearby Agoura High School.
Gordon said the fire was sparked at about 4:15 p.m. PT, when a pickup truck struck a power pole on Mulholland Highway in Calabasas.
"Witnesses reported that the truck was traveling at a high rate of speed before colliding into a power pole, causing the pole to fall and a transformer to explode, thus igniting the Calabasas fire," he said.
Temperatures in nearby Topanga reached the mid-90s earlier in the day, according to the National Weather Service.
The fire, which has been dubbed the "Old Fire" due to its proximity to Old Topanga Canyon Road, was 15% contained as of late Saturday local time, according to the LA County Fire Department.
More than 300 firefighters were battling the blaze, according to Los Angeles Fire Captain Roland Sprewell.
Fighting blaze with garden hoses
Steve Gentry, a photojournalist who filmed firefighters battling the blaze, told CNN the situation was "very serious."
"At one point the fire was licking right up through to the back yards of a lot of the homes of the residents in that area to the point where even sheriffs' deputies were grabbing garden hoses and using them to fight the fire," he said.
"Things here in California, they're very dry and it doesn't take a whole lot for a fire to get going and spread really rapidly."
Pictures of the current blaze show residents staring at bright, tall flames creeping toward the sky, visible from nearby streets.
Roseann Bleiweiss' son told CNN the fire looked like "something out of a movie."
One social media user said ash could be spotted as far away as Dodger Stadium, which is about 30 miles away.
Some celebrities are chiming in on the fire as well.
Ellen DeGeneres tweeted that her brother-in-law was out fighting the fire.
"Sending thanks to Portia's brother Michael (and) all the rescue workers on the scene of this dangerous fire," she said.
The fire came right up to the edges of Calabasas High School and Viewpoint School, which said on its website that it would close all of its Saturday campus events.
Calabasas and the nearby Santa Monica Mountains are no stranger to wildfires -- the area has experienced many dangerous blazes over the years.
A particularly strong blaze in 2013 burned nearly 28,000 acres in two days, threatening thousands of homes in Ventura County.
From 1925 through 2012, 343 fires have been documented, according to the National Park Service.