9/11 anniversary: New York remembers

Nearby, 3,000 flags which had been planted in the park as a "field of remembrance" fluttered in the breeze.

For Joe Zammataro, who travelled from Florida to take part, the 10th anniversary marks a new, inspiring beginning.

"Everyone who visited Ground Zero afterwards, prior to the reconstruction, felt a sense of loss and hollowness," he said. "But now sadness is replaced with hope.

"Holding hands, there was a spirit and energy I felt surge through my body. It was a resurrection, an uplifting feeling.

"They can knock us down but they can't knock us out. That's not the American spirit but the human spirit."

There were private expressions of grief too, like the woman who wiped a tear from her face as she looked up at the new tower, or the retired fire fighter who tried to compose himself on the subway platform.