Tell me about it! I blew myself off the porch of our hunting cabin once.....I must have been around 20 at the time.
I was shooting a Parker-Hale Enfield Musketoon and paused to refill my powder flask from a can of FF BP.
I loaded/capped as normal and when I fired I found myself laying out in the yard, the first thing I saw was a cloud of BP smoke billowing up under the roof of the porch.
I collected myself off the ground (rifle in hand) and the best I can figure is I forgot to affix the cap on the can of BP properly when I set it back down in my ML box (a old wooden ammo crate) as it was blown to hell and gone. I found what was left of the can and it was missing it's lid.
I suspect when I fired a piece of the top-hat cap or spark must have found it's way in and Kaboom!
It blew me through two porch rails, bruised me up good, and blackened my jacket a bit, but otherwise I was none the worse for wear.
LOL....I had to go out and cut me two locust rails to replace the ones I busted and repaint the porch.....From then on I put my new ML box
inside the cabin.....Lesson learned!