Twenty-year-old gunman Adam Lanza killed 26 people, including 20 young children, at a U.S. school where his mother worked Friday in one of the worst school shootings in the country’s history.

People are comforted near Sandy Hook Elementary School, Friday, Dec. 14, 2012 in Newtown, Conn. A man killed his mother at home and then opened fire Friday inside the elementary school where she taught, massacring 26 people, including 20 children, as youngsters cowered in fear to the sound of gunshots echoing through the building and screams coming over the intercom.