> Previous major wildfires have been sparked by: mower blades, rims of flat tires sparking on pavement, catalytic converters parked over dry grass, sparks from a hammer. And electrical equipment.
> Fear of insects. A rancher tried to plug a wasp’s nest in the ground by jamming a stake into the ground. That unleashed a spark that began burning waist-high grass. He tried to smother the flames by tossing a trampoline on it, but that just worsened the flames. It caused the start of the largest of two fires that merged to become California’s largest wildfire on record, the Mendocino Complex fire, which burned more than 450,000 acres in four Northern California counties — Colusa, Lake, Mendocino and Glenn.
A citation:
* https://www.latimes.com/california/story/2019-10-29/how-do-w...
Another one:
> Fear of insects. A rancher tried to plug a wasp’s nest in the ground by jamming a stake into the ground. That unleashed a spark that began burning waist-high grass. He tried to smother the flames by tossing a trampoline on it, but that just worsened the flames. It caused the start of the largest of two fires that merged to become California’s largest wildfire on record, the Mendocino Complex fire, which burned more than 450,000 acres in four Northern California counties — Colusa, Lake, Mendocino and Glenn.
The above was Mendocino:
* https://en.wikipedia.org/wiki/Mendocino_Complex_Fire