A man and two teenage boys suffered burns Friday in an explosion during a school field trip to a desert campground in the eastern reaches of San Diego County, authorities reported.

The blast in the 200 block of Palm Canyon Drive in Borrego Springs happened shortly after 9 a.m., apparently when flammable fumes wafted into a campfire, according to Cal Fire.

The victims were part of larger group from High Tech High School in Point Loma.

“Something caused it to flash,” said Nick Schuler, a battalion chief with the state agency. “The report is there was some propane or some alcohol nearby, and when I say alcohol, I don’t mean the drinking kind, but fuel of some type.”

High Tech High. Photo credit: hthmappublishing.org.

Medics airlifted the 39-year-old man, who suffered second-degree burns over about 30 percent of his body, and the two 14-year-olds to UCSD Medical Center in San Diego. It was unclear how severely injured the boys were, though the trauma apparently was limited to their legs, Schuler said.

– City News Service