This is a report on the Fire of 1910, which burned over 3,000,000 acres/4,700 sq. miles over a weekend. (Likely started by flaming cinders from a steam train.) The Camp Fire burned about 100,000 acres. The 1910 fire lead to the fire suppression policies by the US Forest Service that ultimately contributed to current fires. (These were co-opted by the timber industry, so it is not clear what the forest service on its own might have done through time as it saw the effects of the policies.) But the nature of temperate coniferous forests is that they burn, and even in a state of nature, large areas may burn. As with flooding, it is only an issue when people enter the picture, turning a natural phenomenon into a disaster.
The 1910 fire was not the biggest or most deadly:
Fire resistant construction and community design is not significantly more expensive than conventional construction and has additional benefits by increasing resistance to wind damage. It is pretty expensive to retrofit, however. The principles have been known for a long time, but the political will to impose the construction standards has been limited. Our insurance folks will know better, but at least until the most recent fire seasons, the cost of fire insurance has not been high enough in these areas to incentivize better construction. Part of the reason is that the homeowners and their communities do not pay the cost of firefighting, which usually can save the houses. Thus the risk is subsidized, as with flood insurance and flood control projects. (Fire insurance for high end homes in fire areas does include the cost of firefighting, which is what brings in those private teams to foam the house and the area when a fire threatens.)