Wind-Driven Flames Burn Homes, Force Evacuations : Fires: More than two dozen houses are hit in blazes around the Southland. The dangerous weather conditions could last through Wednesday.

Santa Ana winds gusting up to 50 m.p.h. swept the Southland on Monday, whipping up fires that destroyed or damaged more than two dozen houses and forced evacuation of scores of homes and an elementary school.

Firefighters in Los Angeles, Riverside, and San Bernardino counties battled the wind-driven blazes that destroyed eight homes as temperatures rose into the high 80s and low 90s and the relative humidity plummeted from a morning high of 76% at the Los Angeles Civic Center to 13%.

Authorities issued a red-flag fire alert for mountain and hillside areas because of the combination of drought-dry brush, heat, wind and low humidity.

Meteorologists predicted that strong winds could continue into Wednesday.

Gusts up to 30 m.p.h. fanned a blaze that destroyed four homes and damaged two others in Diamond Bar on Monday afternoon. The 20-acre fire, possibly started by illegal fireworks, started in heavy brush on a slope and swept toward the homes.

“It was moving pretty quick,” Los Angeles County Fire Capt. Bob Grafton said. “Dry winds were pushing it.”

The four houses that were destroyed were two-story structures on Redgate and Shade Hill drives. All had wood-shingle roofs, fire officials said. About 280 county firefighters, using water-dropping helicopters and bulldozers, brought the flames under control at 5 p.m.

“I saw the fire and the next thing I know, within five minutes, it had reached my house,” said Cindy Derr, 34, a massage therapist, whose home was heavily damaged.

Derr said she had time to grab her 8-year-old son and two dogs and escape. But she lost several pets--a turtle, two rats and an iguana--trapped in their cages in an upstairs room. “I just couldn’t carry the cages,” she said.

George Azpeitia, 42, said he noticed the fire about 3 p.m. as flames spread toward his home from his next door neighbor’s house in the 1700 block of Redgate. Azpeitia said he unsuccessfully tried to fight the flames with a garden hose. “It’s devastated,” he said, hugging his wife, Blanca, as they stood outside their heavily damaged home. “But it’s not the end of the world.”

Los Angeles County Fire Battalion Chief Ray Hall said the fire may have been started by fireworks. “We talked to a couple of kids who said they saw some skyrockets go off and then saw the fire come up the hill. But we haven’t been able to locate anyone who set them off,” he said.

In nearby San Dimas, fire erupted in a garage at the rear of a 150-unit townhouse complex in the 12500 block of Meadowglen Lane and was spread by high winds to the wood-shake roofs of three homes, which Los Angeles County firefighters could not save. Residents of the homes escaped without injury. The blaze was attributed to a faulty clothes dryer.

County fire Inspector John Lenihan said “this could have been a repeat of the Sept. 15 West Covina fire” in which 70 units in an apartment complex were destroyed in a wind-whipped blaze.

In Riverside County, a 125-acre fire gutted one house, damaged 17 others and forced evacuation of 40 to 50 homes and an elementary school, authorities reported. The cause of the blaze was labeled “suspicious.”

Five people, including two firefighters, suffered injuries, ranging from heat exhaustion to a fractured shoulder, said Riverside Fire Capt. Ed Couchman.

The fire started about 10 a.m. in a brush area of De Anza Narrows Park, just south of the Santa Ana River. Whipped by 20- to 25-m.p.h. winds and fed by dry cottonwood trees and bamboo, it spread rapidly, climbing a 65-foot bluff and reaching $150,000 homes overlooking the park.

About 150 people were briefly evacuated to a nearby church, Couchman said. Students at nearby Mountain View Elementary School school were sent home.

“The winds just whipped it into a frenzy,” said Faye Dalman, 62, whose home on Grassy Trail Drive had minor damage.

Randy McMillin, 32, said he returned home from work Monday morning to find 50-foot palm trees lining his block aflame. His wife, Mary, had been told to evacuate.

“They said, ‘Grab whatever you can and get out,’ ” Mary McMillin said. “I got my wedding pictures, our guns and personal things.”

Their home escaped damage.

About 200 firefighters from the City of Riverside, Riverside County, San Bernardino County and prison crews were called to the fire, which was reported contained about 5 p.m.

Some residents in the fire area complained that they had been asking the county for a year and a half to clear brush from the county park, but nothing had been done.

“They said it was going to damaged the natural habitat (of birds),” said John Dalman, 61, Fay Dalman’s husband.

In San Bernardino County, about 150 firefighters battled a fire that raced through 148 acres of brush-covered land along the Cajon Canyon foothills, briefly threatening the Tree House Fun Ranch nudist colony.

By Monday evening, winds had died down, and firefighters were able to contain the blaze just short of Glen Helen Regional Park, said Greg Cooper, spokesman for the California Department of Forestry and Fire Protection. Cause of the fire was under investigation.

Another fire in San Bernardino County forced evacuation of 100 people in Duncan Canyon north of Fontana, authorities said. Winds reaching 30 m.p.h. fanned flames across grass-covered fields. A shed was destroyed.

Fires were reported in Santa Barbara and Orange counties, but no homes were threatened.

Meteorologist Steve Burback of WeatherData, Inc., which provides forecasts for The Times, said that Santa Ana winds are “frequent this time of the year” when high pressure forms over the Great Basin and winds flow toward areas of low pressure off the Pacific coast. The upper-level winds are heated as they flow toward the sea, picking up velocity as they are funneled through the mountain passes, he said.

Times staff writers Russell Ben-Ali, Greg Braxton, Irene Chang, Henry Chu, Darrell Dawsey, Nieson Himmel and Tracy Wilkinson contributed to this article.