A lot of my guys get off work (for fire calls) and they don't get paid. It's money out of their pockets. But in this county we have a great group of volunteers who show up all the time.
You should burn very cautiously. If you're burning your trash off, for example in a 55-gallon drum, the big thing is to keep a screen over it and watch for any embers that pop out.
A fire needs three things to survive fuel (like weeds or dry grass), oxygen and a heat source. A lot of grass fires are preventable.
It's not just luck. The homeowners, farmers and ranchers are doing what they're supposed to do.