Crane operators hoisted the final pieces atop the One World Trade Center which will soon tower over the Big Apple.
The top of the metal beacon will crown One World Trade Center, New York's 1,776ft tower, which is due to be one of the tallest buildings in the Western Hemisphere once the spire will be fixed on skyscraper.
The spire was pulled up along the building, the American flag fluttering in the wind, in the glorious sunshine. New Yorkers stopped to watch the symbolic moment at the site of terrorist attacks more than a decade ago.
Officials at the Port Authority, which controls the World Trade Center site, have not yet announced a new date for the symbolic event - which will make the building stand exactly 1,776 feet tall (541.3m).
When the final piece is in place, the spire will measure 408 feet in length and weigh 800 tons.
It will serve as a broadcast antenna for television and radio channels, replacing that which once stood atop one of the Twin Towers and was destroyed during the 9/11 attacks.
Keen snapper Jay, from New York, USA, said: "I was driving home and saw something hanging down this street so went for a closer look.
"Fortunately I had my camera with me and managed to get a few shots. If it wasn't rush hour I would probably have been ushered away pretty quickly but everyone was really busy."
The 104-story building is due to open in 2014.