On a hot July evening last year, a rancher tried to use a hammer and stake to plug a wasps nest.
The hammer slipped, a spark flew, and a patch of dry grass ignited, according to the Los Angeles Times. Within minutes, the brush fire fed on bone-dry conditions and became too big to control.
It soon merged with another blaze and became the Mendocino Complex Fire, the largest wildfire in Californias history.
It burned almost half a million acres, or roughly 720 square miles, before it was finally extinguished four months later. It killed one firefighter and injured four.