With the "meteor shower" challenge there's no fires started. All that really happens is that there are a bunch of space rocks laying about the house and yard, a bunch of ash piles in the house and a bunch of burn marks on the floor to clean up. Occasionally an item of furniture will be destroyed, but I've only had this happen once or twice.
A cleaning service will stop by after the game has been running a few minutes, offering their services. If you accept their help, a maid will come in and pick up a few of the ash piles and mop up a few of the scorch marks on the floor. When they leave, they will comment on the fact that you now have less work to do.
Edit: Come to think of it, it was the firemen who offered to clean up.
