At the National School Safety Conference in an Orlando hotel in 2018, the Washington Post reporter John Woodrow Cox surveyed the wares of “entrepreneurs, corporations and charlatans” peddling various inventions designed to mitigate the deadly effects of school shootings. School security is now a nearly $3 billion market and the vendors offered, among other things, “bleeding control bags,” bullet-resistant white boards, pepper ball guns, counterterrorist marksmen (“for the price of a Netflix subscription”) and bulletproof classroom doors that, it was claimed, could identify a weapon, photograph a shooter and notify the police, at $4,000 dollars a pop.These numbers suggest the scale of the physical, mortal toll inflicted, but they cannot account for the psychic price paid by kids who live in the dark, long shadows of the aftermath of such violence: those who lose a friend or relative to gunfire; who witness gun deaths at close quarters at a vulnerable age; whose lives, and life chances, are shaped by a premature brush with mortality. And since such children were not struck by a bullet, they are not counted and, at least in any official sense, do not count.Ava decided to write to Tyshaun when she saw her mother cry after reading Cox’s story about him in The Post. Cox follows the children’s relationship as they FaceTime, bombarding each other with heart emojis, sending gifts (including stress toys), and commiserating and comforting each other as they open up about their “bad weeks.”Gary Younge is a professor of sociology at the University of Manchester and author of “Another Day in the Death of America.”