One World Trade Center

A spire was fully installed atop One World Trade Center on May 10, bringing the New York City structure to its symbolic height of 1,776 feet. It will serve as a world-class broadcast antenna and also as a beacon to ward off aircraft.

The building is at the northwest corner of the site where the twin World Trade Center towers were destroyed in the Sept. 11, 2001, terrorist attacks. (AP)


Workers prepare to raise the silver spire atop the 1 World Trade Center building in New York early Friday May 10, 2013. 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. When it is fully installed on the building’s roof, it will bring the iconic structure to its full, symbolic height of 1,776 feet. (AP Photo/Mark Lennihan)

Workers pose for a photo prior to raising the silver spire atop the 1 World Trade Center building in New York early Friday May 10, 2013. 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. When it is fully installed on the building’s roof, it will bring the iconic structure to its full, symbolic height of 1,776 feet. (AP Photo/Mark Lennihan)

The final piece of spire is hoisted to the roof of One World Trade Center, Thursday, May 2, 2013 in New York. The piece will be attached to the spire at a later date, capping off the tower at 1,776 feet. (AP Photo/Mark Lennihan)

The final piece of spire is hoisted to the roof of One World Trade Center, Thursday, May 2, 2013 in New York. The piece will be attached to the spire at a later date, capping off the tower at 1,776 feet. (AP Photo/Mark Lennihan)

WTC spire

WTC spire

WTC spire

WTC spire

One World Trade Center, center, rises above the National September 11 Memorial and Museum at the World Trade Center, Thursday, Sept. 6, 2012 in New York. Tuesday will mark the eleventh anniversary of the terrorist attacks of Sept. 11, 2001. The World Financial Center is on the left, and Four World Trade Center is at right. (AP Photo/Mark Lennihan)

An American flag flies next to One World Trade Center, Tuesday, Dec. 11, 2012 in New York. A 408-foot spire is expected to rise on top of the tower into the Manhattan sky by spring. (AP Photo/Mark Lennihan)

An American flag flies next to One World Trade Center, Tuesday, Dec. 11, 2012 in New York. A 408-foot spire is expected to rise on top of the tower into the Manhattan sky by spring. (AP Photo/Mark Lennihan)

A barge loaded with sections of spire for One World Trade Center, left, is guided by tugboat across New York Harbor from New Jersey's Port Newark, Tuesday, Dec. 11, 2012 in New York. The nine pieces each weigh 70 tons. The spire is expected to rise into the Manhattan sky by spring. (AP Photo/Mark Lennihan)

A barge loaded with sections of spire for One World Trade Center, left, is guided by tugboat across New York Harbor from New Jersey's Port Newark, Tuesday, Dec. 11, 2012 in New York. The nine pieces each weigh 70 tons. The spire is expected to rise into the Manhattan sky by spring. (AP Photo/Mark Lennihan)

World Trade spire

Sections of the crowning spire for One World Trade Center arrive on a barge on the Hudson River on December 11, 2012 in New York City. The barge is carrying nine pieces of steel that will eventually top off One World Trade Center out at a symbolic 1,776 feet, becoming the tallest building in the Western Hemisphere. (Photo by Mario Tama/Getty Images)

World Trade spire

Parts of the spire for the Freedom Tower make their way on a barge from Port Newark to lower Manhattan where they will be unloaded and installed on top of the Freedom Tower starting tomorrow on December 11, 2012 in New York City. The barge is carrying nine pieces of steel that will eventually top off One World Trade Center at a symbolic 1,776 feet, becoming the tallest building in the Western Hemisphere. (Photo by Chris Pedota-Pool/Getty Images)