Full Special: ‘America Remembers 9/11: 20 Years Later’

Twenty years ago, America came under attack. Thousands of lives were lost, and the nation was forever changed. In commemoration of the 20th anniversary of 9/11, NBC News NOW is going in depth with comprehensive special coverage. We'll hear heart-breaking stories from first responders, and survivors, emotional reaction from families who lost loved ones, and how the victims of that fateful day are still being remembered.