It normally starts off very small like this 7%, they have to get a beach-head as it were and get SOME boundaries set up, then it's just a matter of extending th

It normally starts off very small like this 7%, they have to get a beach-head as it were and get SOME boundaries set up, then it's just a matter of extending that boundary, such that it can't grow anymore and then it mostly puts itself out. That's the very high level, skipping loads of important details overview of how they tend to fight fires.