CHERRY VALLEY, Calif. -- Firefighters are continuing to battle the massive Apple Fire, which burned at least 20,516 acres in California by Sunday.
CAL FIRE and Riverside County Fire Department officials earlier said the blaze was 12% contained, but San Bernardino National Forest officials later updated that figure to 0%.
Officials said at least two outbuildings were destroyed by the blaze, which began shortly before 5 p.m. Friday. No injuries have been reported.
Responding firefighters in the air and on the ground attacked the flames in an effort to protect the 2,500 homes that were threatened. Crews performed water drops from helicopters, dropping 19,000 gallons of flame retardant on Saturday to help establish containment lines and protect firefighters on the ground.
Earlier in the day, firefighters contained some of the fast-moving blaze, which was downgraded Sunday morning from 15,000 acres burned to 12,000.
The cause of the fire is under investigation, but authorities say it likely may be a case of arson. Officials say the blaze may have started after two suspected arson fires merged into one on Friday.
"It's kinda scary. I mean, it's not scary but I'm angry," Bryan Quan said. "Honestly, I'm angry that somebody could intentionally light this. It burns me."
Steep and rugged terrain made it difficult for crews on the ground to access the front lines. High temperatures and low humidity levels fueled the flames, which were scorching the brush that hadn't burned in years.
"Lots of oils in, so when it's going up these canyons, it's creating all that heat because of those oils and those fuels," said Cal Fire Capt. Richard Cordova. And what you'll see is these big plumes of smoke going up, especially the darker (ones), and once it gets into the atmosphere, it'll start creating its own weather."
Residents in areas under evacuation orders, like Craig Parker, were hoping the fire wouldn't spread toward their homes.
"As long as the wind stays down, I don't think it'll go much further," said Kristy Gastelum. "They should be able to hopefully get a handle on it."
Nearly 2,600 homes, totaling some 7,800 people, were affected by the evacuation orders, fire officials said. Fire officials said they do not have a time frame for repopulating evacuated areas.
"The fire made a good run last night, threatened a lot of the homes," Capt. Fernando Herrera of Cal Fire Riverside said.