America's "what the hell is wrong with people?" moments are piling up.

We have three new ones. Locally, the week started with the near-disaster at DeKalb County’s McNair elementary school, where a man managed to get through the door with a deadly weapon and enough ammunition to kill most of the people in the building. It ended amid the trial of a Brunswick teenager charged with shooting a 13-month-old boy in the face as he sat in a stroller.

Nationally, there was the news of an Australian-born student-athlete gunned down, allegedly by three Oklahoma teenagers who explained to police, “We were bored.”

Some people want to tie the McNair incident to last year’s massacre at Sandy Hook elementary in Newtown, Conn., and argue the problem is the availability of powerful firearms. Others see in the Oklahoma case, where victim Chris Lane was white and two of the accused teens were black, and even in the Brunswick case, in which baby Antonio Santiago was Hispanic and the accused killers black, conspicuous reticence about race on the part of those who literally screamed bloody murder about the killing of Trayvon Martin last year.

Each group misses the larger truth.

Take those cases together, for instance, and you have two gunmen wielding “assault weapons” people wanted to ban after Sandy Hook, and three with firearms that would have remained legal. You have a white gunman killing mostly white students and teachers; a white gunman terrorizing mostly black students and teachers; two blacks and a white killing a white; a black killing a Hispanic; and a Hispanic killing a black in claimed self-defense.

Try to make sense of all five cases on racial or gun-control grounds. You can’t. There’s no way to fool yourself into feeling safe based on your race or the potential outlawing of this or that kind of firearm.

No, what’s most terrifying about the cases of Sandy Hook and McNair, Martin and Lane and Santiago, is their reflection of a social depravity that cheapens, even disregards, life itself.

The Sandy Hook shooter’s parents were divorced, and he was estranged from much of his family. The McNair gunman’s father was long since out of his life, and his mother died three years ago while on probation for burglary convictions. There’s been no mention of fathers participating in the lives of the young men charged with killing the defenseless Lane and the baby Santiago.

The situation with Martin and George Zimmerman is a little trickier to fit into the above pattern, at least regarding their families. But it’s stunning that an overzealous neighborhood watchman and a teenager who took exception to being watched could wind up in a fight that ultimately cost one of them his life.

There were big, powerful guns in America a long time before Americans started using them in this way. And Lord knows race has been a tragic, trying part of our national story from the start.

What has changed is the hastening decline of the family, the foundation of any functional society.

What does it say about us that we think we’re more likely to ban guns, in a country where there’s already almost one for each person, or to have a transformative “national conversation” about race, in a nation with such a tortured racial history, than to address our deteriorating social foundation?

There are lots of possible answers, but I’m afraid there isn’t a good one.