The key to identifying the cause of the still-raging Palisades Fire lies on the tree-covered hilltop where the blaze broke out just after 10:30 a.m. Tuesday.
Fire investigators are still working to determine what started the fire, but experts say it’s easy to rule out one common cause of wildfires: lightning. The area has been free of inclement weather this week. The area near the Temescal Ridge Trail also appears to be devoid of power lines or transformers, ruling out another possible cause.
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That leaves the source of most wildfires: people. But was this the result of arson? Four experts interviewed by NBC News said that’s a possibility, but they believe the fires were likely not intentional.
“This is what we call rugged, inaccessible terrain,” said Rick Crawford, former battalion chief for the Los Angeles Fire Department. “Arsonists typically don’t make it 500 feet through trees and brush, start a fire and run away.”
Fires break out in the wooded areas on the outskirts of Los Angeles all the time, and a lot of them Unintentionally caused by homeless people. Fires never turn into destructive conflagrations due to the lack of strong winds. The combination of high winds and a dry landscape created ideal conditions for the fast-moving fires that burned through large swaths of Los Angeles this week.
“You don’t need a gang of arsonists to go out there and start fires because nature takes care of that for you,” said Scott Fisher, a retired federal law enforcement arson investigator.
He added: “There are arsonists, but is there a gang of arsonists roaming Los Angeles right now? Not likely.
However, arson is a well-known phenomenon. Experts said they would not be surprised if one of the small fires that broke out after the Palisades Fire was deliberately set.
“When you get a big fire like this “Being experienced in Los Angeles, sometimes you push people to go out and start 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 other experts said those answers are unlikely to come anytime soon, because determining arson requires a lengthy investigation.
Eaton fire
Experts say the Eaton fire, the second-most devastating in Los Angeles, is not among the blazes likely to have been started by an arsonist. The volcano erupted on Tuesday evening in the eastern Altadena area, with a group of high-voltage transmission lines hovering overhead.
Given the area and weather conditions, fire experts said their first thought was power lines. Strong winds can cause the lines to collide with each other, dropping small balls of super-hot molten metal.
“If the ground is really dry and the wind is blowing and blowing, you’re going to have a fire,” said Ed Nordskog, a retired Los Angeles County Sheriff’s Department detective who spent his career investigating arsonists.
But this is just one possible scenario. It could also have been started by someone operating a camping stove, car or lawn mower that shot a hot spark onto dry grass, Nordskog said.
As for the possibility that the order was placed intentionally, Nordskog said it was unlikely.
“Most of the time, these fires are not intentional,” he said. “There is no data to support winds that take out arsonists.”
“Inch by inch”
Experts say determining the cause of a fire is a highly specialized and painstaking endeavor.
The first step is to determine where you started. Things like burn patterns and charred debris can provide important clues.
Then comes the most detailed and labor-intensive part of the process. Investigators will place a net at the scene, usually with string, and literally crawl on their hands and knees looking for footprints or other evidence.
Investigators often use metal detectors, magnifying glasses or even binoculars to aid in their search.
“They will go inch by inch by inch, and it will take hours,” Nordskog said. “It’s not fun.”
In the case of the Eaton fire, investigators will likely use magnets to help them look for small pieces of melted metal that could be knocked down by power lines if they collide with each other. Nordskog said the presence of metal does not necessarily indicate the cause of the fire.
“You still have to know if the spark from the power lines was actually the fire or the cause of the fire,” he said. “There are a lot of things going on during an investigation, a lot of factors. If anyone tells you right away what caused the fire, they must have seen it.”
If investigators find evidence that a fire was caused by a person, they must then work to determine whether it was the result of an accident, negligence, or an intentional act.
John Apatzoglou, a professor of climatology at the University of California, Merced, examined 30 years of government data on fire incidents from Los Angeles County. It showed that the most common causes of wildfires from 1992 to 2020 were mishaps involving vehicles and other equipment.
“More than 95% of them are human-ignited fires,” he wrote in an email. “Arson is among the causes, but most human-caused fires are not intentional.”
“The best players out there”
The possibility of arsonists in Los Angeles gained traction on social media Thursday when a group of people in Woodland Hills arrested a man they suspected of starting a dumpster fire. Police officials said Friday that the man had been arrested, but there was not enough probable cause to charge him with arson. He was arrested on a felony probation violation instead.
In addition to the Palisades and Eaton fires, four others burned throughout Los Angeles. The causes are still under investigation.
A law enforcement work team was formed to uncover the causes of the fires. The local agencies involved — the Los Angeles fire and police departments and the county police department, as well as Cal Fire — are among the most skilled in the country. The Bureau of Alcohol, Tobacco, Firearms and Explosives is leading the investigation.
“Everything is absolutely on the table,” Los Angeles County Sheriff Robert Luna said at a news conference on Saturday.
It may take several days for investigators to determine the causes of the fires. Experts said that determining whether a fire set by someone was a criminal act could take several months or even years.
With the number of deaths from the fires reaching 24, efforts to uncover the causes are expected to continue as long as it takes.
“You’re going to have the best players to be able to solve the problem,” said Crawford, the retired Los Angeles Chiefs.