Accident?,muzzle not pointed in a safe direction,finger on the trigger, not familiar enough with the gun,reckless handling of a gun,stupid, I can think of alot of things, but accident,no. A bare bones gun safety class may be all thats legally nessasary to apply for a permit in alot of places.The danger in that is then these people think their trained and competent. The amount of training you get from a class like that might get you a permit, and the training you don't get will get you an eternal dirt nap.