Dec. 14, 2017: It's been five years since the massacre at Sandy Hook Elementary School. We look back and explore how that day became burned into our consciousness, and we remember the 26 victims. Plus, what the end of net neutrality will really look like; a look at Tina Smith, the woman who will replace Sen. Al Franken; what you need to know before healthcare enrollment ends on Friday; why some climate scientists say a "brain drain" is happening under President Trump.