There was an actor, many years back probably in the late 80s, who was horsing around on set w.an actual blank gun and jokingly put the gun to his temple. Fired the blank, and I believe he wound up dying.
Theman, that was Jon Eric Hexum. That was a case of an actor horseplaying with a prop, and no one being able to stop him.
I wrote a version of a Christmas Carol, set in the US and about kids and dope. One scene had a drive-by, suggested by the use of spotlights and a sound effects tape of gunfire. Also, in the segment of Christmas future, the mother had a Johnny Walker bottle with IBC cream soda (flat) and a CO2 pellet pistol, (no pellets or CO2 cykinder.) She exited the stage, then a sound effect of one gunshot was played. No danger to anyone.