On this date (January 27) in 1945, the Soviet Army liberated Auschwitz (wiki). Below are two documentaries (one short, one full length) and links to a few articles. Do the world a favor and educate your kids and grandkids about this - the schools don't do much with it anymore.
Disturbing content warning for these videos:
A short documentary about the liberation:
Longer (45 minute) documentary:
Powerful Portraits Of Auschwitz Survivors Mark 70th Anniversary Of Their Liberation.
Auschwitz Survivor Gena Turgel Walked Out of Gas Chamber Alive.
Spielberg highlights anniversary of Auschwitz liberation.
History.com's Auschwitz page has links to stories, videos, and more.