controlled burn

Recently I took a hike with my children on a path that had been freshly subject to a controlled burn.

Controlled burn.

Oh how my daughters peppered me with questions of how a controlled burn works. They are too young to know how burning works at all but they are old enough to know that the interesting (or certainly more practical) question isn’t why things burn but how one can stop something that is burning. Intuition points to fires burning until there’s nothing left to burn. That’s what fires do.

So, they asked, why didn’t the entire forest burn down?

Who puts the control in the controlled burn?

I did not know the answers to their questions.