The Mythbusters negligently discharged a canon, firing a canonball right though a suburban home, situated 700 yards from their test range, and before bouncing off another house and into a minivan.
This is a classic negligent discharge, I should never have happened. Col. Cooper’s 4th rule of gun safety is “Identify your target, and what is behind it“. If your weapon is a huge piece of artillery, your target is a flimsy concrete barrier, and behind the target is a neighborhood, then you don’t fire!
[ Many thanks to Rob, Sven & Blake who sent this in. ]