Classes canceled as Etiwanda fire rages near Rancho Cucamonga

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Hot shot crews traverse the burned terrain while looking for smoldering embers on the second day of the Etiwanda fire in Rancho Cucamonga. (Gina Ferazzi / Los Angeles Times)

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Firefighters watch the progress of the Etiwanda fire as unpredictable winds feed flames over hundreds of acres. (Robert Gauthier / Los Angeles Times)

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Firefighters cover their faces as smoke from the Etiwanda fire burns in the area along Banyan Street in Rancho Cucamonga. (Gina Ferazzi / Los Angeles Times)

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A brush fire burns near some homes along Indian Wells Place in Rancho Cucamonga. (Luis Sinco / Los Angeles Times)

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Residents evacuate on Macon Drive in Rancho Cucamonga as a wind-driven wildfire burns in the Day Canyon area. (Gina Ferazzi / Los Angeles Times)

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Fire crews battle a brush fire at the front of the Etiwanda fire in Rancho Cucamonga. (Gina Ferazzi / Los Angeles Times)

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Jeannine McClendon takes photos of smoke billowing from the Etiwanda fire as she prepares to evacuate from her home in Rancho Cucamonga. (Luis Sinco / Los Angeles Times)

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Brian Vanstone of Riverside tries to keep his balance along a stucco wall as the Etiwanda fire burns close in Rancho Cucamonga. (Gina Ferazzi / Los Angeles Times)

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A San Bernardino County sheriff’s deputy races from home to home to evacuate residents on Macon Drive in Rancho Cucamonga. (Gina Ferazzi / Los Angeles Times)

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Smoke from the Etiwanda fire billows behind homes along Scarlet Way in Rancho Cucamonga. (Luis Sinco / Los Angeles Times)

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John Martinez carries his belongings in a garbage bag as he prepares to leave his home on Macon Drive in Rancho Cucamonga. (Gina Ferazzi / Los Angeles Times)

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A firefighter walks along Macon Drive in Rancho Cucamonga as smoke from a brush fire obscures homes and limits visibility. (Luis Sinco / Los Angeles Times)

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A wildfire burns across a field of brush in the Etiwanda Preserve in Rancho Cucamonga. (Luis Sinco / Los Angeles Times)

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A San Bernardino County sheriff’s deputy patrols a roadblock as the Etiwanda fire burns along Banyan Street. (Gina Ferazzi / Los Angeles Times)

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Smoke rises from a brush fire burning in the San Bernardino National Forest as seen from the parking lot of Chaffey College in Rancho Cucamonga. (Patrice L. Roe / Los Angeles Times)

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People watch the fast-moving Etiwanda fire in the San Bernardino National Forest from Haven Avenue in Rancho Cucamonga. (Patrice L. Roe / Los Angeles Times)

By Robert J. Lopez and Christine Mai-Duc

April 30, 2014 10:28 PM PT

Classes at four high schools were canceled for Thursday because of poor air quality caused by a wildfire raging out of control in the San Bernardino National Forest near Rancho Cucamonga.

The Etiwanda fire was fanned by powerful Santa Ana winds and had charred at least 1,000 acres of parched chaparral-and-brush-covered hillsides after breaking out Wednesday morning in the Day Canyon area, fire officials said.

The winds had calmed Wednesday night, but hot spots could be seen flaring up, according to television news footage.

Earlier in the day, winds were 60 mph to 80 mph with one gust up to 101 mph, the U.S. Forest Service said.

Classes at Etiwanda, Alta Loma Rancho and Los Osos high schools were canceled for Thursday, officials with the Chaffey Joint Union High School District said.

More than 700 firefighters were battling the blaze on the ground. Water-dropping helicopters and fixed-wing tankers were assigned to the incident but were unable to fly because of the high winds, fire officials said.

Earlier in the day, roughly 1,650 homes were evacuated as deputies went door to door to warn residents, and firefighters scrambled to knock down flames and chase spot fires that were caused by the strong Santa Ana winds.

Mandatory evacuations were lifted Wednesday evening for the hundreds of residents who were forced to flee flames and smoke. Fire officials said voluntary evacuations were still in place for homes north of Hillside Road between Haven and Milliken avenues.

As huge clouds of smoke billowed Wednesday afternoon, Barbora Konecna watched as a half-dozen firefighters worked around her Banyan Street home, clearing brush and spraying water on its roof. All of the sprinklers in the yard were on, dousing the vegetation and eucalyptus trees that surrounded the two-story house.

The 40-year-old Konecna saw some smoke when she left her house about 8 a.m. to take her children to school, but said she didn’t think much of it. By the time she returned home to grab her kids’ forgotten snacks, the smoke was thicker and the winds were blowing it directly toward her house.

Konecna packed up her family’s documents and important belongings, and called a friend to figure out how to turn on the safety sprinklers that came with her house. The firefighters arrived soon after, parking two rigs on her property.

“Any time they tell me it’s time to go, I can get out of here. I don’t want to be in anyone’s way,” she said. “With the wind going the way it is, you just don’t know.”

The blaze exploded in size over the morning, from 20 acres when it was first reported shortly after 8 a.m. to more than 800 acres by midday as winds whipped along steep terrain.

The South Coast Air Quality Management District, meanwhile, issued a smoke advisory for portions of western San Bernardino and Riverside counties.

robert.lopez@latimes.com

Twitter: @LAJourno