LOS ANGELES (AP) — The death of a firefighter on the lines of a wildfire east of Los Angeles was under investigation Friday as another blaze to the north threatened small communities on the edge of the Mojave Desert.

The death occurred Thursday in San Bernardino National Forest as crews battled the El Dorado Fire about 75 miles east of LA, the U.S. Forest Service said in a statement.

The fire erupted earlier this month from a smoke-generating pyrotechnic device used by a couple to reveal their baby’s gender, the California Department of Forestry and Fire Protection, or Cal Fire, said.

The name of the firefighter was being withheld until family members are notified.

“Our deepest sympathies are with the family, friends and fellow firefighters during this time,” Forest Service spokesperson Zach Behrens said in the statement.

No other information was released about the firefighter, the agency the firefighter worked for, or the circumstances of the death.

A Cal Fire statement said it was the 26th death involving wildfires besieging the state.

More than 18,500 firefighters were battling more than two dozen major wildfires in California on Friday as a cold front moving through the western states was causing gusty winds.

In northern Los Angeles County, winds were gusting at more than 30 mph as the Bobcat Fire threatened the communities of Juniper Hills and Paradise Springs after burning all the way across the San Gabriel Mountains to the desert.

“We have aircraft, crews and equipment doing everything they can to slow the spread,” Angeles National Forest tweeted.

On the south side of the fire, firefighters continued to protect Mount Wilson, which overlooks greater Los Angeles and has a historic observatory founded more than a century ago and numerous broadcast antennas serving Southern California.

A new fire was growing in wilderness outside Palm Springs.

More than 7,900 wildfires have burned more than 5,300 square miles in California this year, including many since a mid-August barrage of dry lightning ignited parched vegetation.

The El Dorado Fire has burned more than 33 square miles and was 66% contained, with 10 buildings destroyed and six damaged.

Cal Fire said earlier this month that the El Dorado Fire was ignited Sept. 5 when a couple, their young children and someone there to record video staged the baby gender reveal at El Dorado Ranch Park at the foot of the San Bernardino Mountains.

The device was set off in a field and quickly ignited dry grass. The couple frantically tried to use bottled water to extinguish the flames and called 911.

Authorities have not released the identities of the couple, who could face criminal charges and be held liable for the cost of fighting the fire.

Shortly after the fire began, San Bernardino County District Attorney Jason Anderson issued a statement saying he was aware of the community’s concerns about how the fire started.

“If investigative reports are filed with our office, we will review all facts, evidence, statements, and reports to determine what criminal charges, if any, need to be filed,” Anderson said.

In 2017, a massive Arizona wildfire was accidentally started by an off-duty Border Patrol agent who shot a target filled with an explosive blue powder at a gender reveal.

The fire burned 73 square miles (189 square kilometers) and caused $8 million in damage, The agent was charged with a misdemeanor and sentenced to probation.