I appreciate both responses.
Yes, a HS game. I'm a relatively new umpire and was working the bases in A (2 umps system) so, when hit, I checked the path of the ball then stepped in watching for a play at 1st. I didn't see the bat hit the catcher, but my partner, a very experienced umpire called the batter runner out immediately, for what he described as a forcefully slung bat. It was the final out in a run rule loss for the home team so, game over. I certainly understand the safety issue but haven't found the precise rule for this situation.