Because it’s something you can actually react to. There’s almost no chance a tornado will hit your school but schools do tornado drills. All schools and busines

Because it’s something you can actually react to. There’s almost no chance a tornado will hit your school but schools do tornado drills. All schools and businesses do fire drills. There was a time they did nuclear bomb drills and many buildings from the era have fallout shelters. So yes it’s unlikely to occur. But it could and it requires very little effort to be prepared.