During the summer, the local news (this is a local story for me) reported someone crashed a quadcopter in a vacant field starting a 2 acre grass fire. Many local news reports suggested the quadcopter pilot was at fault.
But there was more to the story – two off leash dogs came running across the field up to the drone pilot and jumped up on him, causing him to become distracted and lose control of the quadcopter. The quad crashed resulting in sparks igniting dry grass. The source of sparks is not clear from the news report – hot parts? friction between the blades and the ground? battery fire?
The operator immediately called 9-1-1; the quad flyer was not charged with anything.
If flying in dry areas, it is a good idea to be prepared. At our model aircraft flying field, we have fire extinguishers, a water faucet, and buckets of sand. The latter is used to smother Lithium-polymer battery fires.