A mass shooting at an elementary school in Uvalde, Texas has left at least 18 children and three adults dead. We break down what we know tonight with reporting from outside the school. Also, the mother of a Sandy Hook elementary student who was killed in the mass shooting there in 2012 joins Shep to talk about what parents can do to help their children and her efforts to help communities with the Jesse Lewis Choose Love Movement. And Frank DeAngelis, the former principal of Columbine High School, on how the school took action after a mass shooting killed 12 students and a teacher in 1999.