The key to identifying the cause of the still-raging Palisades Fire lies on a brush-covered hilltop where the blaze broke out just after 10:30 a.m. on Tuesday.
Fire investigators are still working to determine what sparked the inferno, but experts say it’s easy to rule out one common cause of wildfires: lightning. The region was free of stormy weather this week. The area near the Temescal Ridge Trail also appears to be free of power lines or transformers, which rules out another potential cause.
That leaves the source of most wildfires: people. But was it a result of arson? Four experts interviewed by NBC News said it was a possibility, but they thought the fires were more likely not set on purpose.
“This is what we call inaccessible, rugged terrain,” said Rick Crawford, former battalion chief for the Los Angeles Fire Department. “Arsonists usually aren’t going to go 500 feet off a trailhead through trees and brush, set a fire and then run away.”
Fires break out in the wooded areas on the edges of Los Angeles all the time — many of them caused unintentionally by homeless people. The fires almost never grow into a destructive blaze due to the lack of high winds. The combination of ferocious winds and a parched landscape created ideal conditions for the fast-moving fires that have consumed large swaths of Los Angeles this week.
“You don’t need a gang of arsonists to go out there and be starting fires because nature is taking care of that for you,” said Scott Fischer, a retired federal law enforcement arson investigator.
“There are arsonists out there,” he added, “but are there a band of arsonists running around Los Angeles right now? Not likely.”
Copycat arson is a known phenomenon, however. The experts said they wouldn’t be surprised if one of the smaller fires that broke out after the Palisades blaze was intentionally set.
“When you get a large fire event like this being experienced in Los Angeles, you sometimes trigger people to go out and light a fire,” said Terry Taylor, a retired wildland fire investigator who now works as an instructor. “It’s a copycat thing. ... It happens from time to time.”
Taylor and the other experts said it’s unlikely those answers will come anytime soon, as determining arson tends to require a lengthy investigation.
Eaton Fire
The Eaton Fire, the second largest to wreak havoc in Los Angeles, is not one of those likely to have been started by an arsonist, the experts say. It erupted Tuesday evening in an area east of Altadena where an array of high-voltage transmission lines hovers overhead.
Given the area and weather conditions, the fire experts said their first thought was power lines. Whipping winds can cause the lines to slap together, shedding small balls of superhot molten metal.
“If the ground is really dry and the wind is blowing and poof — you have a fire,” said Ed Nordskog, a retired detective with the Los Angeles County Sheriff’s Department who spent his career investigating arsonists.
But that’s just one potential scenario. It’s also possible that it was started by a person operating a camping stove or a car or lawn mower that ejected a hot spark onto dry grass, Nordskog said.
As for the possibility it was intentionally set, Nordskog said it was unlikely.
“Most of the time, these fires are not arson,” he said. “There is no data supporting winds bringing out arsonists.”
‘Inch by inch’
Identifying the cause of a fire is a highly specialized and painstaking endeavor, experts say.
