How Wildfires Start (Hint: It's Usually Not Arson)
Supervisor Bill Horn publicly aired suspicions that one or more of the blazes was set by an arsonist. But even if one or more of the current fires was intentionally set, statistics show it’s actually pretty rare for wildfires to start on purpose with some nefarious aim.
As flames from several wildfires whipped through North County this week, Supervisor Bill Horn came forward with a bold suspicion: The blazes may have been started by an arsonist still on the loose.
“I question whether or not six fires haven’t been set by somebody,” Horn said Wednesday at a news conference in Carlsbad. “I’ve never seen anything like this in 20 years.”
Horn admitted “it could all be by chance” and said he did not have any evidence that arson was the cause. Fire Captain Kendal Bortisser later said the arson suspicion “did not come from Calfire” and that “the fires are under investigation.”
Horn said early on Thursday, though, that he’s not the only one with that worry, he just “probably spoke up first about it.”
Indeed, arson is often where people’s minds drift when blazes break out. But even if an arsonist did set one or more of the current local fires (10News reported Thursday that an arson suspect in Escondido had been questioned and released), statistics show it’s actually pretty rare for wildfires to be set on purpose with some nefarious aim.
The state’s largest wildfire in history, the Cedar Fire in San Diego County in 2003, was started by a man who eventually argued he was lost and set the blaze in hopes of being found.
The Cedar Fire scorched 273,246 acres, destroyed 2,820 structures and killed 15 people.
Even the cause of that fire, though, is listed officially as “human related” – not specifically arson.
Statistics from recent years suggest only a small percentage of wildfires in San Diego County battled by Calfire are set intentionally. Of 162 wildfires listed under Calfire’s Wildfire Activity Statsitics for 2012, only seven were determined to have been caused by arson. In 2011, it was six of 196 and in 2010, it was seven of 136.
But the cause of dozens of wildfires each year in the county goes undetermined, according to Calfire.
Not including the “undetermined” and “miscellaneous” categories, the three primary causes of San Diego County wildfires battled by Calfire in 2012 were equipment use (16), debris burning (15) and lightning strikes (12).
Jennifer Jones, a spokesperson for the U.S. Forest Service, said that wildfire causes differ greatly by region.
“Back in the southern and eastern parts of the country,” Jones said, “debris burning is a huge cause of wildfires.”
Lynne Tolmachoff, a spokesperson for Calfire, said that the primary cause of wildfires in California often depends on the time of year. Leaves don’t fall as heavily here as they do in other states, but burn piles are a big cause of wildfires during times residents are permitted to do so.
“During the rest of the year, it’s a lot of unintentional starting fires … things like lawn mowing,” Tolmachoff said. “But 95 percent of the fires in California are human-caused.”
And Southern California, Tolmachoff said, is where the larger and more destructive fires are “because of the weather pattern and wild land urban interface.”
Horn said one of the reasons he believes arson may have been a factor in the blazes currently burning is because there does not seem to be much connecting each one.
Fire officials are “looking for evidence,” Horn said. “If it’s there, we’ll find it … All I have is a gut feeling.”