That’s sort of like asking why Minnesotans don’t close schools on the forecast of snow, isn’t it?
Well, not really. I’ll take snow over a tornado any day. This weather event was almost a given. The weather forecasters all predicted there would be tornadoes, so I still don’t understand why they would have school today. It may even be the last day, for all I know, so there was nothing going on anyway. Very sad for all involved.
One thing is for sure - if you want to have a thriving new suburb in these “tornado alley” areas - your school needs to have a large underground “tornado proof” place with room for all the kids - and a wide access hall/tunnel to get to it (to avoid bottle necks).
Big expense but it will pay for itself - and it can be used for other stuff in good weather.
That’s what I’d be looking for.