The fact that you think this is something you should be concerned about when sending your kid to school shows that you lack critical thinking and base your idea of the US on agenda pushing media instead of rationality.
Even in the US your kids are not likely to get shot unless they're involved with youth drug gangs, that's where most of the child gun deaths come from. In France they trade the mass shooting incidents in for truck or bomb attacks.
This is an honest to God, real reply to that question :D