Yes, rarely there are shootings and violence. My school has 5th grade safety's. They go around the school and have posts to make sure everyone is ok. Bullying is the worst common thing in school these days... It's not like a kid walks around school with a gun in his bag.
We've all seen schools aren't a safe place anymore. Everyone needs to be vigilant. Be on the look out for people doing or saying things out of the ordinary. Don't be a bully. Take a stand against bullying. That's about all you can do