When I was 16 I had a Ruger Super Single Six. I had gotten a B-Square scope base and a dot sight for it for Christmas. Sitting in my room on the bed, got it out of the drawer, opened the gate, spun the cylinder a few times to check it. Didn't see the dirty brass, and it wasn't a well lit room. Got the scope mounted and dry fired four times out the window. Fifth dry fire found its way through the window and into the side of my neighbors garage.
Scared the crap out of me and everyone else in the house. Was a great Christmas. To this day I do t know why it only had one round in it. Never was in the habit of keeping it loaded. Guess I got distracted when I had last put it away.