'9/11: One Day in America' features a 6-part docuseries in words of survivors

PHILADELPHIA (WPVI) -- It's hard to believe we are coming up on two decades, but to commemorate the 20th Anniversary of 9/11, National Geographic is debuting a four-night, six-part documentary series this Sunday.

It's called '9/11: One Day in America'.

This is an in-depth, first-person account of survivors. It's their stories, in their words.

"It was really to kind of give an unflinching account, and honor and respect the lens of those who survived it," says TJ Martin, an executive producer of the series.

"If you watch the film, the only voices you ever hear are from people who were there on the day," added co-executive producer Caroline Marsden.

This is about the victims. This is about the survivors. This is about American history.

"In the course of watching it, you're getting the granular details from so many different points of view from individuals," Martin says. "They are incredible tales of survival from individuals who were on the 80th floor of South Tower, the first responders, even members of the media who showed up to document the events and feel it in real-time."

There's so much tragedy to unravel, so much trauma, but also, a sense of hope.

"The hope comes from across the board, from all different kinds of walks of life, points of views and different experiences," Martin says. "The amount of selflessness that was displayed was surprising in the best of ways."

"9/11 : One Day in America" debuts this Sunday, 8/29 on National Geographic. It will also be streaming on Hulu.

Watch below for my full interview with the executive producers.

Executive producers talk about their documentary to commemorate 20 years after the 9/11 terror attacks. National Geographic presents the groundbreaking documentary series.