Ten years ago, a mass shooting forever changed the small town of Newtown, Connecticut. Twenty students and six educators were killed at Sandy Hook Elementary School in one of the worst mass shootings in U.S. history. William Brangham spoke with one of the parents who lost a child that day. Stream your PBS favorites with the PBS app: https://to.pbs.org/2Jb8twG Find more from PBS NewsHour at https://www.pbs.org/newshour Subscribe to our YouTube channel: https://bit.ly/2HfsCD6 Follow us: TikTok: https://www.tiktok.com/@pbsnews Twitter: http://www.twitter.com/newshour Instagram: http://www.instagram.com/newshour Facebook: http://www.pbs.org/newshour Subscribe: PBS NewsHour podcasts: https://www.pbs.org/newshour/podcasts Newsletters: https://www.pbs.org/newshour/subscribe