CASTAIC, Calif. – Firefighters fought to maintain the upper hand on a huge and rapidly moving wildfire that swept through rugged mountains north of Los Angeles and resulted in more than 50,000 people being put under evacuation orders or warnings.

The Hughes Fire broke out late Wednesday morning and in less than a day had charred nearly 16 square miles (41 square kilometers) of trees and brush near Lake Castaic, a popular recreation area about 40 miles (64 kilometers) from the devastating Eaton and Palisades fires that are burning for a third week.

Though the region was under a red flag warning for critical fire risk, winds were not as fast as they had been when those fires broke out, allowing for firefighting aircraft to dump tens of thousands of gallons of fire retardant on the latest blaze. By Wednesday night, about 14% of the Hughes Fire had been contained.

“The situation that we’re in today is very different from the situation we were in 16 days ago,” Los Angeles County Fire Chief Anthony Marrone said Wednesday evening.

Red flag warnings were extended through 10 a.m. Friday in LA and Ventura counties. Officials remained concerned that the Palisades and Eaton fires could break their containment lines as firefighters continue watching for hot spots.

More than 31,000 people have been ordered to evacuate from the Hughes Fire, and another 23,000 are under evacuation warnings, LA County Sheriff Robert Luna said. There were no reports of homes or other structures burned.

Parts of Interstate 5 near the Hughes Fire that had been closed reopened Wednesday evening.

A 30-mile (48-kilometer) stretch of the major north-south artery had been closed for emergency vehicles, to move equipment and to prevent accidents due to smoke billowing across it. Crews on the ground and in water-dropping aircraft tried to prevent the wind-driven fire from moving across the interstate and toward Castaic.

Marrone said that because winds were not as strong as they were two weeks ago, aircraft crews were able to drop fire retardant on the south side of the fire, where the flames were moving, he said. More than 4,000 firefighters were assigned to the fire, he said.

Winds in the area were gusting at 42 mph (67 kph) in the afternoon. They had reached as high as 65 mph (105 KPH) in some mountain pockets by Wednesday night, according David Roth, a meteorologist with the National Weather Service.

Kayla Amara drove to Castaic’s Stonegate neighborhood to collect items from the home of a friend who had rushed to pick up her daughter at preschool. As Amara was packing the car, she learned the fire had exploded in size and decided to hose down the property.

“Other people are hosing down their houses, too. I hope there’s a house here to return to,” Amara said as police cars raced through the streets and flames engulfed trees on a hillside in the distance.

Amara, a nurse who lives in nearby Valencia, said she’s been on edge for weeks as major blazes devastated Southern California.

“It’s been stressful with those other fires, but now that this one is close to home it’s just super stressful,” she said.

To the south, Los Angeles officials began to prepare for potential rain even as some residents were allowed to return to the charred Pacific Palisades and Altadena areas. Gusty weather was expected to last through Thursday and precipitation was possible starting Saturday, according to the National Weather Service.

“Rains are in the forecast and the threat of mud and debris flow in our fire-impacted communities is real,” Supervisor Kathryn Barger said during a Wednesday morning news conference.

Fire crews were filling sandbags for communities while county workers installed barriers and cleared drainage pipes and basins.

Los Angeles Mayor Karen Bass warned that winds could carry ash and advised Angelenos to visit the city’s website to learn how to protect themselves from toxic air during the latest Santa Ana wind event. LA County public health director Barbara Ferrer cautioned that the ash could contain heavy metals, arsenic and other harmful materials.

“Even a brief exposure can potentially cause skin irritation and lead to more serious problems,” Ferrer said Wednesday, asking people to wear protective gear while cleaning up.

The low humidity, bone-dry vegetation and strong winds came as firefighters continued battling the Palisades and Eaton fires, which have killed at least 28 people and destroyed more than 14,000 structures since they broke out Jan. 7. Containment of the Palisades Fire reached 70%, and the Eaton Fire was at 95%.

Luna said Wednesday that his department was still investigating 22 active missing person reports in both fire zones. All of those reported missing are adults, he said.

The federal Bureau of Alcohol, Tobacco and Firearms is investigating the causes of the fires but has not released any findings.

Several lawsuits have been filed by people who lost their homes in the Eaton Fire, alleging Southern California Edison’s equipment sparked the blaze. On Tuesday, a judge overseeing one of the lawsuits ordered the utility to produce data from circuits in the area where the fire started.

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Weber reported from Los Angeles. Associated Press journalists Ethan Swope in Castaic, Hallie Golden in Seattle, Jaimie Ding in Los Angeles and Julie Walker in New York contributed to this report.