Aug. 14 (UPI) -- A fast-moving brush fire in northern Los Angeles County has grown to 11,000 acres, threatening thousands of structures, officials said.
The Lake Fire, which erupted Wednesday afternoon near Lake Hughes, about 65 miles north of Los Angeles, has grown to 11,000 acres and was only 5% contained, the Los Angeles County Fire Department said in its Thursday night update.
Some 5,420 structures remained threatened by the blaze, which has already destroyed three buildings, the department said.
Evacuation orders are in place for Lake Hughes Road West of Pine Canyon and North of Dry Gulch Road, East of Ridge Route Road, West of Lake Hughes Road and Fire Station 78, North of Pine Canyon and Lake Hughes Road and South of SR-138.
Seneca Smith, public information officer for Angeles National Forest, said the fire has been driven by dense and dry vegetation and steep terrain and that it's been hard to predict if it will continue to grow and in what direction.
More than 1,000 people were working to contain the fire on Thursday, she said, with more resources on the way.
"What we are seeing as far as priorities go with this type of fire behavior is we're working on perimeter control of the fire and structure protection," she said in a video published to Twitter.
Fire crews on Thursday took advantage of slightly lower temperatures and moisture from Tropical Storm Elida moving across the area but warmer and drier conditions are forecast for Friday, officials said.
"Near critical fire weather conditions could develop Friday afternoon and evening as gust onshore winds could combine with warm and dry conditions in place," the Los Angeles County Fire Department said in its update. "Rugged terrain with drought-stricken fuels, heavy fuel loading and high temperatures have contributed to the difficulty of suppressing the fire during the initial attack period."
Angeles National Forest Chief Robert Garcia said there have been a few small fires in the area before but much of it hasn't burned since the late 1960s.
Meanwhile, firefighters were battling a second fast-moving brush blaze in southern California dubbed Ranch Fire that ignited Thursday and had grown to 3,000 acres in the San Gabriel Mountains, about 50 miles northeast of Los Angles, with 0% contained by nightfall.
Angeles National Forest said in a statement that "structures are threatened."
Evacuations had been ordered for Mountain Cove but were lifted by 11 p.m., the Azusa Police Department said.