by Sandy Grady

About the author: Sandy Grady is a writer for the Philadelphia Daily News. Her column is syndicated in newspapers throughout the United States.

Their names were Natalie, Brittany, Stephanie and Paige Ann. In photos they wear fresh, impish smiles of 12- and 11-year-olds peddling Girl Scout cookies or heading for a pajama party.

You look at their pictures—and the placid smile of heroic teacher Shannon Wright, who shielded another child—and every face comes at you with a jolting puzzle.

The faces of the dead ask, “Why"”

Answers don’t come easy. The faces strike you with baffled anger. Why would a couple of pint-size Rambos in camouflage outfits grab an arsenal of rifles and fire 27 high-powered slugs—as though the crowd of school children...