A deadly wildfire roaring through mountains north of Los Angeles for a sixth day more than doubled in size on Monday and posed a lingering threat to Mount Wilson, a broadcast and communications hub and the site of an historic observatory, Reuters reported.
Two veteran firefighters died on Sunday when they were overrun by flames in the Angeles National Forest and rugged San Gabriel Mountains. Nearly 2,600 firefighting personnel, some from as far away as Montana and Wyoming, have been assembled to battle the blaze.
The burned area ballooned to 105,000 acres from 42,000 acres reported late on Sunday, and the fire continued to encroach on the 5,700-foot (1,740-meter) peak of Mount Wilson.
Fire crews were removed from the summit, home to 50 buildings plus a world-famous array of telescopes and a critical cluster of transmission towers for broadcasters.
"They've done everything they can do and it's unsafe for them to be there when the fire hits," Los Angeles County fire Captain Mark Whaling said.
Elsewhere in the forest, 65 firefighters retreated from a wall of flames advancing on their positions, Whaling added.
At least three more structures were reported lost overnight in addition to 18 houses destroyed on Sunday, said Scott Visyak, spokesman for the California Department of Forestry and Fire Protection, or CALFire.
The fire threat eased in some foothill communities of suburban Los Angeles that were menaced by flames over the weekend, as well as in the town of Acton, on the opposite side of the massive fire farther to the north, officials said.
But 200 to 300 homes on the southwest flank of the fire, just inside Los Angeles city limits, were newly threatened on Monday and ordered evacuated, city fire Capt. Steve Ruda said.
Throughout the fire zone, residents of some 4,000 dwellings were under orders to leave their homes, said Stephen Whitmore, spokesman for the Los Angeles County sheriff.
Five people who defied those orders, four men and one woman, ended up trapped in their home surrounded by flames as they awaited rescue on Monday, with sheriff's deputies waiting to get them out "when we can," Whitmore said.
"What were they thinking?" he said. "When we tell you to leave, leave. This is not a joke."
The first day of classes for two nearby school districts, Glendale and La Canada, were canceled due to heavy smoke.
While the blaze more than doubled in size, fire officials said crews had managed to create buffer zones around many of the neighborhoods that had been most at risk.
"Where the fire has burned up to the edge of communities, and firefighters have put it out, they're obviously in much better shape," Whaling said. "They're not out of the woods until we get the entire area mopped up."
The fire as a whole was just 5 percent contained and may not be fully contained for another eight days, officials predicted. The cause of the fire was under investigation.
The blaze was fueled by dense, tinder-dry vegetation that had not burned in several decades, triple-digit temperatures and low humidity. The saving grace of the situation so far has been a lack of fierce Santa Ana winds that have fanned many of Southern California's worst wildfires in the recent past.
Three civilians were reported injured over the weekend, including two who failed to heed evacuation orders and sought shelter in a hot tub when flames converged.