Although California is pretty prone to earthquakes only about 10 percent of Californians actually have earthquake insurance.
So that means only 90 percent of Californians or California residents have earthquake insurance coverage even though everyone who lives in California and owns property there should have earthquake insurance added to their homeowners insurance policy.
But lately California has been having many more wildfires than they have earthquakes so right now people who live in California are more at risk of their home burning down due to the wildfires instead of the earthquake destroying their home.
But if you do own a home and don't have earthquake insurance and an earthquake damages or destroys your home the regular homeowners insurance policy will not cover the cost of the damage.