GD: Programming: Exploding Barrels ahoy!

In Programming we have to come up with a basic 'Exploding Barrel' idea: i.e., an item that will react once when shot, and then explode when hit. The idea is that this 'barrel' must fit the theme of our level, so of course I'm going to do a post box!

When shot once, the post box will merely burn lightly. When hit more solidly, it will explode in a puff of spinning letters! Here's to hoping I can get the letter particle effect to work in a cool manner.