On one of my first trips to New York a good few years ago, one of the places I was keen to visit and pay my respects was Ground Zero, and the site of the World Trade Centre. The area was still under re-construction at the time and it was a surreal and moving experience to visit the site. One of the walkways gave a clear view of the foundations of what would later become the new Freedom Tower, or One World trade Centre. It was quite shocking to see in person for the first time when you suddenly got a sense of the scale of what had happened.
I had actually forgotten about this shot, but I came across the photo again recently while sorting through my Library.