Loud applause and cries of joy erupted from construction workers assembled on a temporary work platform on the roof of the building as the huge, silver spire was gently lowered and secured into place.
"It's a pretty awesome feeling," Juan Estevez said from a temporary platform on the roof of the tower where he and other workers watched the milestone.
"It's a culmination of a tremendous amount of team work ... rebuilding the New York City skyline once again," said Estevez, a project manager for Tishman Construction.
Image: The 408-foot spire at the top of One World Trade Center is seen from lower Manhattan, Friday, May 10, 2013 in New York. The tall, heavy spire was fully installed Friday, bringing One World Trade Center to its symbolic height of 1,776 feet. (AP Photo/Mary Altaffer)