Researchers are combing the charred hillside to solve a mystery: How did the Palisades Fire start?

A week later, the Palisades Fire tore through the mountainside, consuming entire communities and killing at least eight people. Its cause remains unknown.

The answers, as they emerge, are a charred, blackened ridge overlooking the Pacific Palisades neighborhood of West Los Angeles, encompassing a popular walking trail: Along the line is the site of a small fire six days ago .

Understanding the deadly Jan. 7 fire could take months, a process in which investigators gather video and photos from nearby homes and social media, interview witnesses and firefighters and review 911 calls, began with a search for leaders.

“This all takes time,” José Medina, acting special agent in charge of the Los Angeles office of the Bureau of Alcohol, Tobacco, Firearms and Explosives, said at a news conference Tuesday. He said there are 75 federal and local investigators on the case. “We know everyone wants answers and the community deserves answers. The ATF will give you those answers, but only after we have completed a thorough investigation. “We don’t have a timeline for when that will happen.”

According to multiple law enforcement sources familiar with the investigation, investigators have not reached any conclusions, but the initial phase of the investigation is focused on human factors. Possibilities include arson, an accidental spark, fireworks, unauthorized camping activity or reigniting a fire that was extinguished on New Year’s Day, sources said.

The investigation took investigators to the ash-covered area where the fire was first discovered, searching for even the slightest traces.

Wind-blown wildfires, like the Palisades Fire, leave “motion patterns” on plants, trees, grass, rocks and other objects that show the trained eye how flames spread. By marking these signs, investigators go back to the suspected starting point.

“If you can understand how to read these patterns, the origin of the fire becomes clear very quickly,” said Ed Nordskog, a retired Los Angeles County firefighter who was not involved in the Palisades fire investigation.

Nordskog said investigators are trying to limit the search to an area of ​​about 25 square feet and then divide the area into a network of zones, each about 4 square feet. Using magnets, metal detectors and magnifying lenses, they examine small objects, such as melted machinery parts, match heads, glass and fireworks, that could explain or rule out a potential cause. They can bring a dog trained to detect traces of accelerant. They are also guided by signs from electrical equipment or gas vehicles, such as nearby fences or poles. At the same time, other investigators talk to witnesses who saw something suspicious.

The ATF National Response Team, along with local authorities, has responded to the Palisades Fire, which also burned across Los Angeles County last week and was swept across hillsides and neighborhoods by high winds, destroying more than 12,000 structures. . other fires. It consumes more than 40,000 acres and kills at least 25 people. Some fires are still burning.

The Palisades fire, the largest, may be the most difficult to explain because of the many potential factors that investigators must rule out to determine the cause.

The theory that caused the fire on January 1 is the one that has generated the most public opinion.

The same wildfire, detected by residents of the nearby Palisades Mountain neighborhood, which is part of Pacific Palisades, ignited in the ridge area shortly after midnight. The firefighters put it out before 5 in the morning. considered to exist, no structures were damaged and no one was injured. The city’s transportation department did not say what caused it.

The fire was almost forgotten after six days.

Darrin Hurwitz took a routine walk on a hillside trail near his home in the Marquez Knolls neighborhood around 8:20 a.m. on Jan. 7. It was very windy: officials had already warned that the strong conditions would increase the risk of fires in Los Angeles.

An hour into the hike, as he passed a rock known as Skull Rock, he saw burned vegetation and smelled smoke. Recalling the New Year’s Day fire, Hurwitz said he didn’t think much of it because he could smell it… or assumed he was spotting fires burning farther away.

Hurwitz, a 49-year-old lawyer, said he stopped a few hundred feet from the burn scar and saw no smoke or anything notable. “It wasn’t enough to think there was something suspicious,” he said. Hours later, his family escaped as the fire engulfed the neighborhood, but their home was destroyed.

Mid-morning, a group of followers saw flames and smoke near Skull Rock and took photos and videos as they fled to safety. Palisades Mountain residents said they watched the fire grow from their homes around 10:30 a.m.

The appearance of two fires in the same area about six days apart has fueled speculation that the Palisades fire was caused by a flare-up of the previous one. However, experts are divided on whether this may be true or not. The 2023 wildfire that destroyed Lahaina on the Hawaiian island of Maui was caused by the reignition of a smaller fire, but the fires occurred just hours apart.

Embers can remain hot for days or weeks after a fire, and tree roots can burn underground, Nordskog said. This effect is often seen in montane forests, he said, and is not as common in the coastal scrub of the Pacific Palisades. But it is possible, he said.

Former ATF arson investigator Scott Svitov said he doubts that happened in this case.

He said the relatively light vegetation of the Pacific Palisades landscape and the six days before the second fire started made it “incredibly impossible” for it to reignite.