Students and staff will not be returning to the Uvalde elementary school where a gunman shot and killed 21 people. Classes at Robb Elementary were set to end for the year on May 26, just two days after alleged gunman Salvador Ramos entered the school through an unlocked door and barricaded himself inside a classroom. The 18-year-old suspect unleashed more than 100 rounds of gunfire during the attack, fatally striking two teachers and 19 students. Investigators are currently probing why a self-locking door at Robb Elementary failed to engage after a teacher pulled it shut in the minutes before …