— the seventh deadly school shooting in the U.S. this year and the third deadliest ever behind the Virginia Tech and Sandy Hook massacres, as cell-phone videos surfaced on Wednesday and Thursday of students crouched on a classroom floor, the sound of gunshots echoing in the background, parents across the country have found themselves asking what can they do to protect their kids. For moms and dads glued to news stories wondering, What if it were my kid texting me good-bye from a classroom, buying a bulletproof backpack provides an immediate point of action, a grab at any sense of control over the insanity we’re living in.