WATCH: America marks 25 years since 9|11

Twenty-five years after Sept. 11, 2001, ABC’s David Muir looks back on the day that changed America, and the hope in a phone call decades later.

​Twenty-five years after Sept. 11, 2001, ABC’s David Muir looks back on the day that changed America, and the hope in a phone call decades later.  US Twenty-five years after Sept. 11, 2001, ABC’s David Muir looks back on the day that changed America, and the hope in a phone call decades later.