A wildfire that has burned almost 10,000 acres and forced the evacuation of half a Southern California city was sparked by a pyrotechnic device at a gender reveal party, fire investigators announced Sunday.

The El Dorado Fire, in San Bernardino County, is not the first large wildfire to result from a misguided attempt to announce the sex of an unborn baby. In April 2017, an expectant Arizona father fired a bullet into a target packed with an explosive substance and set off the Sawmill Fire^[1], which burned almost 47,000 acres.

That man — Dennis Dickey, a 37-year-old Border Patrol agent — was convicted of a misdemeanor and ordered to pay $8,188,069 in restitution to those whose property was burned.

The U.S. Forest Service released video of the Arizona incident. A gunshot is heard, and a boxlike target explodes in a cloud of blue powder. Immediately, the dry grass around it bursts into flame, and a man is heard yelling, “Start packing up!”

The explosive in that case was identified as a Tannerite target, a brand that explodes when hit by a high-velocity bullet. Tannerite is strictly regulated in California, with a permit required for its purchase or use.

In the El Dorado Fire, investigators from the California Department of Forestry and Fire Protection revealed few details. They said the fire began at 10:23 a.m. Saturday at El Dorado Ranch Park, just east of the Yucaipa city limit, and that it was caused by a “smoke-generating pyrotechnic device.”

CalFire’s press release referred to a “party;” in an interview with the Associated Press, agency spokesman Bennet Milloy characterized the event as a family outing to record video of the device’s detonation.

He said surveillance video showed the unidentified couple frantically racing to their vehicle to retrieve water bottles once the flames erupted.

“You can’t fight a fire like this with a water bottle,” Milloy said. “They had no chance after it started.”

The couple could be liable for the cost of fighting the fire and criminally charged with misdemeanor or felony counts.