While I am not interested in guns, I disagree with your suggestion that people shouldn't be permitted to own them. I do agree that there should be some pretty tight restrictions on ownership however.
More importantly, I believe that the "little things" that you reference cannot be overemphasized. Families who spend time together, parents who care about their children and take time with them on their school work or other activities seem to be the exception rather than the rule. People don't spend time interacting, in person, with others. Texting or tweeting are now the norm. Perhaps most important is the lack of any recognition of God. I could not help but thinking, upon reading about this incident, that we used to pray in schools, now you send your children to school each morning hoping they'll be safe.