Twenty children and six adults were killed in a shooting at Sandy Hook Elementary School in Newtown, Connecticut on December 14, 2012. The gunman, 20-year-old Adam Lanza, killed his mother at home and then opened fire at the school. He killed himself as police arrived at the scene. President Obama addressed the nation to express sorrow for the victims. Details emerged about the victims, including heroic actions by teachers who lost their lives trying to save students. The nation mourned this tragic loss of life.