Not only can you have a tragic accident, but here in PA, our District Attorney's don't like anyone with cannons. If someone gets hurt or killed through accidental discharge, or explosion, they'll charge the owner with negligent homicide in a heartbeat. A poor fool near Gettysburg is doing 6 years, because his cannon blew up and killed a family member at a 4th of July picnic. State Police told me I need to get a pyrotechnics display license just to legally fire my cannons. Now I don't believe for a second that the guys who "recreate" at Gettysburg get a Pyromanic license to fire their cannons.