What to Know The Saddleridge Fire began Thursday night in Sylmar and spread into the Porter Ranch area to the west

The fire is being fanned by strong Santa Ana winds, which can blow embers onto houses

One fatality was reported and about 25 homes were damaged early Friday

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As wildfires scorch Southern California hillsides, state and local officials have signed emergency declarations in response to several fires that have hit Southern California.

The declarations free up resources to support firefighting efforts in Los Angeles and Riverside counties.

Firefighters worked to protect homes as the fast-moving wildfire spread across parts of the San Fernando Valley, forcing evacuations, threatening thousands of homes and closing major freeways.

Mandatory evacuations affected about 100,000 people and more than 20,000 homes are in place for several communities north of Los Angeles early Friday. Porter Ranch, Granada Hills and Sylmar are under evacuation due to the 7,500-acre Saddleridge fire, which began Thursday night in Sylmar.

Containment was at 13 percent Friday afternoon.

One fatality was reported -- a man who suffered a heart attack during the fire. The man is believed to be in his late 50s.

About 31 structures were damaged.

The fire spread quickly overnight due to strong winds, which can pick up embers and blow them into neighborhoods. Red flag warnings, indicating high fire risk, were extended until 6 p.m. Saturday for parts of Los Angeles and Ventura counties.

"As you can imagine the embers from the wind have been traveling a significant distance which causes another fire to start," LAFD Chief Ralph Terrazas said.

The 118, 5, 14 and 210 freeways are all closed in the area. The northbound side of the 405 Freeway also remains closed.

It was a sleepless night for Porter Ranch resident Gordon Wolf. He arrived at an evacuation center early Friday in Granada Hills.

"It was the smell, and finally a police car came up the street," Wolf said. "My wife pretty well prepared everything. She had everything packed in suitcases. Bless her heart."

Several homes were seen burning in Granada Hills, and the LA fire department said an "unknown number" of homes were potentially threatened.

"We need you to leave," said LAPD Chief Michel Moore. "It will save your life."

There were no reports of injuries.

Some evacuation centers filled up Friday morning as residents, some of whom spent the night away from their homes, waited out the flames. Some homeowners were allowed back into their neighborhoods Friday morning.

Infamous Santa Ana winds returned to Southern California Thursday, combining with dry conditions to elevate wildfire danger across the region. The winds fan flames, contributing to alarming rates of spread and generating some of California's worst wildfires.

Windy conditions are expected through Friday, indicating a busy day ahead for firefighters throughout Southern California.

The Saddleridge fire erupted Thursday night in Sylmar, shutting down freeways and prompting evacuations, including nearly 300 children housed at a juvenile hall, officials said. The children were being evacuated in county transport vehicles and were taken to Los Padrinos Juvenile Hall in Downey, Public Information Officer Kerri Webb said.

The blaze shut down the 210 Freeway where it meets the 5 Freeway in Sylmar. The flames jumped over the 210 Freeway from the westbound to the eastbound side.

Until now, Southern California had been spared the large wildfires that devastated the state last year, when the largest, most destructive and deadliest fires on record burned in California. Above-average soil moisture, steady winter rains and high humidity are some of the reasons, along with onshore winds that help keep humidity in place. Without dry brush that acts as fuel, fires can't spread as quickly.