LLANO (CNS) - Containment of the Summit Fire in the Antelope Valley increased to 53% Tuesday as firefighters continued making progress building control lines and putting out hot spots, while it was reported that illegal fireworks may have sparked the blaze.

Interior pockets of the fire continue to burn while larger fuels smolder and produce visible smoke. Heavy annual rainfall has created a dense fuel bed, and recent winds, high temperatures and low relative humidity has rapidly dried out thinner, smaller fuels, creating a highly receptive fuel bed, officials said.

Suppression crews were operating in steep, rocky terrain, while narrow roads present additional driving hazards. Cal Fire Damage Inspection Teams have completed approximately 90% of the assessments, the agency said.

As of Tuesday, 1,060 crew members were working the fire, according to the Los Angeles County Fire Department.

Meanwhile, a fire official in nearby San Bernardino County said at a briefing Monday that illegal fireworks were suspected as the cause of the fire, according to a published report.

San Bernardino County Fire Assistant Chief Kelly Anderson, who serves as assistant chief of the North Desert Division for the San Bernardino County Fire Protection District, said during an annual fireworks workshop in Adelanto that illegal fireworks sparked the so-called Summit Fire.

A Los Angeles County Fire Department spokesman said Tuesday that he was unable to confirm the report and that the cause of the fire remained under investigation.

As for the continuing firefight, operational priorities Tuesday included maintaining strict safety protocols amid intense heat while monitoring for potential thunderstorm development. Crews will remain vigilant for erratic outflow winds and dry lightning, which could cause unpredictable fire behavior, while continuing to navigate the hazards of steep terrain and rolling debris, according to Cal Fire.

An extreme heat warning was in effect through Thursday evening, increasing the risk of heat-related illness for ground personnel.

The fire was 31% contained Sunday evening when its progress was stopped at 2,690 acres and the lone evacuation order was lifted, authorities said.

The National Weather Service warned of triple-digit temperatures in the area.

Smoke and flare-ups were expected well within the areas that have already burned, officials said.

Evacuation warnings remained in place for two zones between Angeles Crest Highway and state Route 138 on the eastern edge of Los Angeles County, west of Piñon Hills.

"This cautious approach is due to active incoming winds, potential interior fire behavior and a heavy presence of emergency vehicles operating throughout the area," according to a statement from the unified command.

"Road closures will also remain in place. Keeping these warnings active ensures that both fire crews and the public remain safe while critical operations continue," the statement added.

Officials also announced that drones were prohibited over the area while crews were actively working the fire.

The fire has destroyed two structures and damaged seven others, according to Cal Fire.

One firefighter injury has been reported. Details about the seriousness of the injury were not immediately available.

Personnel assigned to the fire were equipped with 74 engines, five dozers and 11 water tenders, according to Cal Fire.

The firefighting effort was being handled under the unified command of the Los Angeles County Fire Department, U.S. Forest Service, San Bernardino County Fire Department, Cal Fire, the Los Angeles County Sheriff's Department and San Bernardino County Sheriff's Department.

Gary and Shannon

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