When the warning came, the classroom doors were quickly locked and the lights turned out. Paper was taped over the door windows. And the kids hunkered down, on the floor, against the walls, out of sight. Within seconds, all that was left in the usually bustling halls of Montgomery Blair High School that day last month was an empty, foreboding silence, as if a killer was afoot. Then, through the quiet, came the sound of someone trying door handles. Down the corridors... (GunPolicy.org)