After having my first ND (and it will be my last) recently I came to the conclusion that almost all of these are preventable. Glad no one was hurt!
Mine went like this. I came in from the backyard after playing with the dog at around 11:45pm. I walked in and noticed the front door hanging wide open. This was VERY alarming as I have a habit of locking EVERY exterior door and window. At any rate, I was very thankful that I had been cleaning my Makarov just a few minutes ago and it was still on the kitchen table. I had unloaded it at my nearby computer desk and then gone to the table to take it apart. I was thanking my lucky stars that I had been so inteligent to have a reliable firearm with ammo nearby.
I began to methodically clear the house. I first checked the garage which is adjacent to the front door. All clear.
Next, I moved back into the house and turned left down the hallway. Both secondary bedrooms were open, so I cleared them first. Both OK, windows locked.
Next, I entered the bathroom. I opened the unlatched door slowly and began to push the shower curtain back when...the dog came running in and jumped up on my left leg. He scared the hell out of me and the gun went off.
Well, thats what I thought at first. I settled down very quickly and started thinking about what I had done wrong. The gun had not jus "gone off." I fired it.
First, my finger was on the trigger. -probably the main cause of this ND.
Next, I didn't excercise due caution as far as the gun being loaded.
I thought my backstop was good...but later became a little more concerned about a miss.
Well, I quickly cleared the rest of the house with the gun at my side and my mag-lite in hand. I then surveyed the damage.
First, the Winchester Supreme SXT JHP (.380 95 grain) went through the shower curtain and liner, then through the fiberglass shower. The bullet went through the drywall behind the shower, nearly 10" of insulation and then through another sheet of drywall. The bullet is now in an open living space approx. 8' wide. The bullet passed through another sheet of drywall, more insulation and exited an exterior wall covered with stucco. The bullet removed a chunk of stucco approx 4" in diameter. I never recovered the bullet.
It did not enter my neighbors house, thank god!!!!
All this from such a supposedly weak caliber.
I filled the 9mm holes with expanding foam insulation and began patching. The fiberglass was actually the hardest to fix as the putty that supposedly dries "white" doesn't actually dry that color. I had to paint it with some white enamel. The drywall was easy as was the stucco.