Fire officials said Thursday that the fire was 20-percent contained and they did not expect it to reach the area, near Big Bear Lake, but the San Bernardino County (Calif.) sheriff's department warned residents to prepare to evacuate if the situation changes, The Los Angeles Times reported Friday.

"They didn't expect it to get this big in the first place," said Bill Stewart, an assistant deputy director of fire research for the state fire agency. "When you have these high winds, it changes the game totally."

The fire, which began as a small scrub fire ignited by lightning and was nursed by the winds and desert heat in the Mojave, has destroyed more than 45 homes and 110 other structures, as well as 47,800 acres of greasewood and Joshua trees since it began to spread Sunday, the Times said.

The 13 mile-wide and 100-foot-tall blaze is possibly the largest wildfire the area has seen in 50 years, Stewart told the Times.