NEW YORK -- The silver spire topping New York City's One World Trade Center has been fully installed on the building's roof.
It brings the iconic structure to its full, symbolic height of 1,776 feet. The addition makes the structure the tallest building in the Western Hemisphere.
The Port Authority of New York and New Jersey says the spire's installation was completed Friday morning. Construction workers applauded the milestone.
Pieces of the spire (which weighs 758 tons) were transported to the roof of the building last week, but weather delayed its installation.
The building's height is symbolic of the year 1776, when the U.S. declared its independence.
The 408-foot spire will serve as a world-class broadcast antenna. An LED-powered light emanating from it will be seen from miles away.
The new tower is at the northwest corner of the World Trade Center site, which is well on its way to reconstruction with the 72-story Four World Trade Center and other buildings.
One World Trade Center, with an observation deck, is scheduled to open in 2014.