UVALDE, Texas (AP) — An 18-year-old gunman killed 19 children and two adults as he went from classroom to classroom at a Texas elementary school. Tuesday’s attack added to a gruesome, yearslong series of mass killings at churches, schools and stores. A law enforcement official said the attacker was killed by a Border Patrol agent who rushed into the school without waiting for backup. The assault at Robb Elementary School in the heavily Latino town of Uvalde was the deadliest shooting at a U.S. school since a gunman killed 20 children and six adults at Sandy Hook Elementary in Newtown, Connecticut, in December 2012.