Ehm, you can't be serious...
If it really happened that way it is all your fault. I mean how can a person not understand the clear meaning of "*YOUR TOWN* will be TOTALLY gone." Isabelle warns you like two hundred times, that everything will be deleted. I seriously don't get it...
PS: That's what I like about this game: if you are about to make a really important decision, the game makes sure you actually understand the consequences. (one might say it is fool-proof... well, apparently not completely...)