Both of these happened to me. The first, a year ago, was a very expensive stunt. And the second, a minor expense, just happened.

1. Leaving the garden hose attached to the outside faucet in freezing weather. Result, a burst pipe which only became known in the spring after it was discovered that all the plant watering was also watering stored items in the basement.

2. Buying soda in 12 packs on sale and then storing them in the garage, and forgetting to bring them in during freezing weather. Result: exploding pop cans and monstrous bulging pop cans. Luckily, everything was still frozen, so cleanup was easy. What a waste.

Oops.