How does a fire turn from a fire to a firestorm?

Answer:
a fire is a burning chemical reaction that is of fairly large size.
a firestorm is when many fires together all over get really big.

like, a sort-of big firestorm could cover the United States.
First answer by Winniethepoohis cool. Last edit by Winniethepoohis cool. Contributor trust: 2 [recommend contributor recommended]. Question popularity: 1 [recommend question].