Who guards our children when they are out of school? In the park? At friends' homes? Home alone?
Learn to live with it. Tragedies happen every day. We can never make life 100% safe but our obsession with that goal is making life less bearable. A child dies in school shooting, or drowns, or killed in auto accident, or house fire, are they not equally tragic. Is the child not just as dead? Do the survivors not grieve just as much. What is the difference? One is a family tragedy, the other is a media event. One is soon forgotten by all but their intimates. The other is exploited for as long as it is profitable.
We have nothing to fear but fear itself.