This man was stupid enough to have gunpowder (Black Powder) sitting loose & open on the loading bench when shooting. A spark from his gun ignited the gunpowder creating a large flash. NEVER have gunpowder sitting on the loading/firing bench. If you are using a powder horn, swing it round behind you & make sure the plug is in the spout. THIS IS PLAIN COMMON SENSE. If you do not posses any common sense, then you should not be shooting in the first place!!!