Ouch, not good. I remember last year in the middle of winter when our hot water heater blew. It didn't explode or anything, but it was gushing water out of the bottom of it and flooded a quarter of our basement. We ended up having to buy a whole new unit because of that, but the good thing was, we only had to pay a very small amount of money since the heater was under warranty. The next heater we get is going to be tankless since I hear those save quite a bit of money on the gas bill.