Thousands of evacuees have been allowed to return home as the nearly 55-square-mile Sand Fire continues to burn in Southern California's Santa Clarita Valley.

Updated Article: Containment Increases to 25 Percent

Firefighters announced that all evacuated residents would be allowed to return home at 7 p.m. Monday, with the exception of Placerita Canyon Road from Running Horse Lane to Pacy Street and Little Tujunga Canyon Road from the Wildlife Way Station to Sand Canyon Road and Placerita Canyon Road.

Large animals were to be allowed to return as well.

The fire has burned about 10,000 acres per day since it began Friday in the hills north of Los Angeles, growing at a rate firefighters described as "almost unprecedented."

"It has averaged about 10,000 acres per day," said Chief Mike Wakoski, incident commander. "An acre is a football field, so imagine that -- 10,000 football fields per day."

Shifting winds have fanned the flames, which raced through neighborhoods and destroyed homes. One death, a man whose burned body was found in a scorched vehicle, was reported in the fire zone.

"This fire, what we've seen in 72 hours, is almost unprecedented," said Los Angeles County Fire Department Battalion Chief Dennis Cross. "We'd have to go back a long way to compare a fire to this. And, we're not through with this thing yet."

Eighteen homes were lost to the fire by Sunday night as thousands were forced to flee their homes, worrying if they would still be standing by Monday. The fire was only at 10 percent containment Monday morning and more than 1,500 homes were threatened.

About 200 more fire engines were deployed Sunday and Monday, adding to the 120 already in the Santa Clarita Valley.

"We're really relying on aircraft and bulldozers out ahead of this thing to try and pinch it off, but as you're seeing with 100-foot flame lengths, it's crossing bulldozer lines, aircraft isn't able to keep it in check and we're playing this game of hopscotch," Cross said.

About 10,000 homes were evacuated and several roads remained closed Monday. Some evacuees were about to return home Sunday when unexpected winds stirred up the blaze that ignited two days earlier in brush withered by days of 100-degree temperatures and years of drought.

Juliet Kinikin said Sunday that there was panic as the sky became dark with smoke and flames moved closer to her home a day earlier in the Sand Canyon area.

"And then we just focused on what really mattered in the house," she told The Associated Press.

Kinikin grabbed important documents and fled with her husband, two children, two dogs and three birds.

The fire is burning in hillsides left dry after five years of drought in California. A strong El Nino weather pattern failed to deliver rain in Southern California, raising concerns about what could be one of the worst fire seasons on record.

Smoke from the blaze blanketed Southern California, causing air quality concerns as ash rained down.

A wildfire burning 300 miles up the coast near Big Sur claimed six homes, burning 17 square miles. It was 5 percent contained by Sunday evening.

Kate Larsen contributed to this report.