60 Minutes: Season 51, Episode 23

51 - 23: Survivors' Network | Pleistocene Park | The Rock

Parents of a 2012 Aurora, Colorado shooting victim travel the country to help others impacted by mass shootings; then, Siberia's Pleistocene Park: Bringing back pieces of the Ice Age to combat climate change; and, German-style program at a Connecticut maximum security prison emphasizes rehab for inmates.