Paul, we ran a similar sized business to the beer distributor where the 9 were killed, and in about 35 years that I was there we had a half-dozen situations that had the potential to go sour as this one did. The difference was that I had two key guys in the building with 9mm Glocks under their shirts. (One was a manager who was also a part-time constable.) We also had a trouble alert code prepared to broadcast over the paging system, and I had a .25 cal. Beretta in my back pocket at all times, with some heavier equipment locked in a safe. For all those years, nobody in the building knew it. (There were a couple of situations where we were waiting for police to arrive and some of them wondered where I got a gun so fast. They never did figure it out.)
We never needed to use them, which means we never shot anybody. But if it had become necessary to protect the lives of the people working for us, we were ready to do that. Not all bosses, or managers, unfortunately, think that way. Some of them are dead.