By ACACIA CORONADO and JIM VERTUNO, Associated Press UVALDE, Texas (AP) — An 18-year-old gunman opened fire Tuesday at a Texas elementary school, killing at least 19 children as he went from classroom to classroom, officials said, in the deadliest school shooting in nearly a decade and the latest gruesome moment for a country scarred by a string of massacres. The attacker was killed by law enforcement.