Fast-moving California wildfire threatens homes, prompts evacuations (Source Reuters) A rapidly expanding wildfire in Northern California is threatening about 150 structures and has forced evacuations in several rural areas as the wind-whipped blaze rips across parched vegetation, officials said on Wednesday. Experts predict an unusually active and destructive wildfire season in California, as the state grapples with a fourth year of crippling drought. The Wragg Fire near Lake Berryessa, some 75 miles north of San Francisco, was sparked around 2:30 p.m. by a vehicle accident, according to CalFire, the California Department of Forestry and Fire Prevention. The fire had expanded to 4,000 acres in about eight hours, and was 5 percent contained, CalFire said. The blaze shut down part of a highway and was threatening 150 homes and other structures, it said. Evacuation orders were issued in several rural areas and a campground, but it was not clear how many people were forced to leave. CalFire said 300 firefighters and four helicopters had been dispatched to battle the blaze as it cut across rugged, steep and brush-covered terrain. Shortly after the blaze broke out, three hikers were rescued from an area south of the lake, CalFire said. There were no immediate reports of injuries. Erratic winds made fighting the fire more difficult, officials said.