For most of the 20th century, the insurance industry considered wildfires to be little more than a benign nuisance. They occurred frequently but rarely resulted in more than a handful of claims, and underwriters priced for them in the same way as other attritional sources of loss like theft, breakage and sewer back-up.
Then in 1991, everything changed.
The 1991 Oakland Hills Fire ($4 billion insured loss) provided the first glimpse of the horrors that a wildfire could bring, killing 25 people and destroying 2,900 structures in less than a day.
Wildfire losses accelerated over the next 25 years with the Cedar, Old, Witch, Butte, and Valley fires collectively destroying 8,300 structures and resulting in more than $5.7 billion in insured damages.