If the person had paid for people to put the fire out, the house wouldn't have been lost. The cost of the loss falls on the home owner too, who now no longer has a home, because they didn't pay a small fee.
community wealth - 1 house. And it will not be the only one.
"If's" aren't gonna change that.
You can't just demand people to do stuff for you - that's slavery. How about the loss of time to the fire fighters? How about their loss of life if they are killed while fighting the fire?
It's the job they accepted to do and are paid for (at least in our society), so it's not slavery.