The two most likely causes of the fires in LA County:

The most likely is the same thing that caused the Paradise Fire and the Lahaina Fire I believe in Maui which is power lines blowing down. On Maui there are wind generators going 24 hours a day from the tropical breezes or more and this I think caused the Lahaina fire eventually.

The Paradise Fire the burned down that whole town was also caused by power lines being blown down.

So, the likeliest cause of the fires in LA County are power lines being blown down.

The 2nd likeiliest cause is someone (maybe a disgruntled person of some kind) who set fire to some of the richest areas of LA County. Many Actors like Jennifer Garner and Billy Crystal for example have or had homes in this area.

I could see someone angry (like maybe a homeless person for example) burning down the lives of people who are well off enough to live in Pacific Palisades or Malibu or Altadena which are all really rich places where homes start off at maybe 2 to 10 million dollars in both of these locations (what it presently costs to buy one there). So, it would make sense that someone with nothing might be angry at those who actually had a good life. So, the motivation would likely be jealousy more than anything else of the wonderful life one can have in places like Altadena or Pacific Palisades or Malibu.

The problem really is only around 60 percent of these 12,000 buildings burned completely down in all these areas have fire insurance. So, the people without fire insurance likely will lose their investments completely of everything they once owned and it will not easily (if ever) be replaced. The same is exactly true of Lahaina and Paradise in California.

For example, even in Paradise California only 1/3 of the houses have been rebuilt likely because the rest didn't have fire insurance which is common way out in the country where people often build their homes with their own hands and if they are able to do this without getting a mortgage often these people do NOT have fire insurance state wide especially out in the country where building your own home is very common. I did this and so did my father and so did my best friend and so did another friend and many other friends in order to never have a mortgage.