In 22:5 it says, "כי תצא אש ומצא קוצים ונאכל גדיש..." - When a fire goes out and finds thorns and the silo will be consumed....
When you light a fire, it is going to do damage. It will find something to burn.
A person has to be careful with his anger, and with his fire. As soon as he lights it, as soon as he lets his anger get out, it is very hard to control. Once let out, it is sure to do damage.