Shooting at School

So a few days ago my site manager claim that he heard shooting from outside a few minutes right after the children and I came in. Now I nor the other children heard it...nor did the principal but stuff like hearing a shooting shouldn't be dismissed just because we didn't hear it. There needs to be an assembly on this. The principal so focused on waxing the floors of the school for a PTA meeting but what about planning a PTA meeting? The next day the site manager told me to keep my ears and eyes open just in case I hear any shootings. Now before we went outside, I spoke to the children about safety and asked them what to do when they hear shooting. Some of them said run but I asked them what if there is stray bullets flying around? That is when I mention that they should lay low. Now I spoke to my friend about it that night and he mention his safety policy when there is a shooting as to how they would go about it. He said run and hide or run in a zig zag to lessen the chance of being hit. When the student said run he didn't mention running in a zig zag.I was thinking of going over a story of when I was little on what I did when I experienced 2 shootings and how no one taught me what to do after the shootings happened especially if you are outside. What do you guys think?