BONSALL (KGTV) — Multiple fires broke out across San Diego County this week, prompting investigators to begin the meticulous process of determining their causes.
It began Monday with the Mission Fire in Bonsall and the Border 6 Fire near Jamul. On Tuesday, the Monte Fire in Lakeside required water drops from aircraft, and on Thursday, the Hawick Fire created smoky conditions in the hills of unincorporated El Cajon.
"Each investigation is different. Different location, different circumstances," said CalFire San Diego Captain Robert Johnson.
I spoke with Johnson about how investigators approach these fire scenes to determine their origins.
Johnson explained that crews constantly survey the environment to rule out different potential causes, checking for nearby electrical poles or old cars that might have sparked the blazes.
"As a fire burns it leaves behind clues that show investigators the direction the fire came from," Johnson said.
These clues include stains or soot on nearby objects. If one side of an object is more burned than the other, that shows which way the fire progressed. Teams then work backwards to locate the fire's origin.
"They're looking at the vegetation, how it burned. If there are specific angles in the vegetation that are charred different or scorched different," Johnson said.
Using these environmental indicators, investigators can narrow down an ignition area. Witness interviews and video footage also frequently assist in the investigation process.
"Some investigations may only take a couple hours, and other investigations if they're more complex and need more followup, can take weeks to months and sometimes even years," Johnson said.
Johnson couldn't provide specific details about this week's fires, noting that the investigations are still ongoing.
