It was a nearly perfect late summer day in New York City on September 11, 2001. At around 8:30 in the morning, it was sunny and about 70, and not a cloud in the sky. What would transpire in the next few hours was a nightmare. It is one of those moments in history where everybody remembers where they were when they first heard, then watched the news in horror as the Twin Towers at the World Trade Center went down and the Pentagon was under attack.

I was working part time for the radio stations in Augusta and also working for LL Bean in Waterville at the time. I had the day off and had a haircut appointment later that morning in Hallowell and was meeting friends after for a round of late summer golf.  I had just gotten out of the shower and was pouring my second cup of coffee when I saw Good Morning America break away from regular programming to report that a plane had hit one of the Twin Towers at the NY Trade Center. Needless to say, none of us felt like playing golf that day, as we were all glued to the news watching things unfold.

Fifteen years later, the images are still etched in my mind.

CNN has prepared a 15th anniversary edition of the extraordinary documentary that features the only video footage shot inside the World Trade Center on that devastating morning.

According to Variety Magazine the backstory of “9/11” is well-known. French filmmakers Jules and Gédéon Naudet and firefighter/director James Hanlon were filming a documentary about a rookie firefighter when they found themselves bearing witness to history. Jules Naudet caught footage of the first plane hitting Tower 1, and he followed firefighters inside the building as the frantic rescue effort began. His camera kept rolling even as the skyscraper collapsed.

CNN will air “9/11: Fifteen Years Later” twice starting at 8 p.m. on Sept. 11.