We'd still have a problem. Adults. Adults text, drink and drive, smoke, and more just like teenagers. If you really want to get rid of the problem than we need people to start raising their kids correctly.
We don't need gun control either, we need people who can do good. If we take the guns away, it will simply just make it harder for them. They will buy guns on streets, steal them from stores and people, and heaven knows what else.
One of the biggest problems of this world: People who don't give a flying pig about people's safety and lives. Their kids and families.