EDIT: I see my post is being downvoted. I know that it may come across as insensitive to immediately leap to the gun control debate, but frankly I'm more angry than upset by this news. How many times does it have to happen? We have a good 48 hours of emotional outpouring and then everyone forgets it ever happened.
There's absolutely no way to prevent people from losing it, so the focus should be on minimizing the damage and finding a good process for dealing with the aftermath.
Politicians don't want to touch it because of votes. There are idiots who vote solely for whoever is against guns, or for them, or against abortion, or for it. That's what really drives every election, very select issues that they abuse to extremes. The media doesn't look for the truth any longer, because why do something new when you can just repeat the same pattern every cycle and milk the shit out of it. When a politician takes a stand, and tries to discuss something real, they are sidelined and derided by their own people. They don't want an honest debate because then they'd have nothing to pretend to argue about.
Guns aren't going anywhere, ever... Any attempt at additional control would only lead to violence. Abortion isn't going anywhere, ever... Not even the supposed anti-abortion politicians have any intent of changing those laws. People need to realize this.
The answer is probably more guns, not less. Any number of armed school personnel could have lessened this nightmare. If you're tasked with protecting children, shouldn't you be prepared for a gun fight?