It's hard to believe that it's been six years since the towers were struck and collapsed, sending clouds of smoke and debris across lower Manhattan, chasing my engineer and me into the confines of our satellite truck.
I've been back to Ground Zero every year since for the remembrance ceremony, except once when I was in Afghanistan at Kandahar Airport, where the Marines had set up a temporary base.
A flag recovered from the World Trade Center debris was sent there, signed with tributes to the troops from first responders, and the Marines raised it on a pole over the main terminal building. It was especially meaningful to witness the ceremony there, with the armed forces tasked with finding, catching or killing the people responsible for the attack.
Later, when the colonel at the base found out I was flying home to New York in a few days, he asked if I'd bring the flag back with me and deliver it to the Marine Corp offices in the city. I told him I'd consider it an honor.
Today, the "pit" is a very different place. It's evolved every year, of course, from a smoking pile of rubble to an empty hole, gradually (and painstakingly slowly) filling with construction equipment, trailers, cranes, train platforms and fresh concrete and steel, as the foundations for the new towers take shape, replacing what once stood so tall and proud.
Covering the story each year brings back a flood of memories and hearing and seeing tape from that morning always gives me chills. It was the worst day imaginable for so many of us, the toughest test for those who responded in so many ways — but it was also a reminder of the strength of the fabric that binds us all together.
So many gave so much, and continued to give all they could in the days and weeks and months that followed. The city was in shock and mourning and still is in many ways, especially on this day. But it's rebuilding in earnest and many are focused on the future, which may be why the rumblings are getting louder that it's time to scale back the ceremony and move on. The debate rages even among family members.
Most will tell you what's most important is that we never forget. If we don't learn from our mistakes, we're destined to repeat them.
I spent a few minutes talking to New York Police Commissioner Ray Kelly after his appearance on FOX & Friends, on the 10th floor balcony of the World Financial Center, just across the street from Ground Zero. I asked him if he thought it was inevitable the site would be attacked for a third time (1993 being the first).
"It's inevitable someone will try," he said. "That's why we're working so hard. To try and prevent it from happening."
Inevitable. Vigilance. Never Forget.
Rick Leventhal has been a New York-based correspondent with the FOX News Channel since June 1997. You can read his bio here.