Parents and families woke up in a nightmare today, after another deadly school shooting took the lives of 19 children and two teachers in the small town of Uvalde, Texas. Authorities say the rampage in Robb Elementary school ended only after a border patrol agent rushed into the school without waiting for backup and killed the lone gunman. The massacre entering the record books as the second deadliest school shooting in US history, following Sandy Hook 10 years ago - we'll get into this devastating news in tonight's Hold the Line.