One World Trade Center nears completion
Goldman Sachs headquarters, left, One World Trade Center, second left, and 4 World Trade Center, center, stand above the lower Manhattan skyline, Wednesday, April 2, 2014 in New York.
One World Trade Center nears completion
The 'Tribute in Light' and Statue of Liberty shine as One World Trade Center rises under construction on the eleventh anniversary of the terrorist attacks on lower Manhattan at the World Trade Center on September 11, 2012 in New York City.
One World Trade Center nears completion
Michelle Murray of Rockaway, New Jersey looks up while standing at the 9/11 Memorial during ceremonies for the twelfth anniversary of the terrorist attacks on lower Manhattan at the World Trade Center site on September 11, 2013 in New York City.
One World Trade Center nears completion
Construction cranes work on the 56th floor of 1 World Trade Center, center left, and Four World Trade Center, right, in New York, Feb. 4, 2011.
One World Trade Center nears completion
A necklace with a cross is seen hanging from a 9/11 Memorial art piece outside a firehouse near the World Trade Center site in New York, Sept. 9, 2014.
One World Trade Center nears completion
A reflection of One World Trade Center is seen from Four World Trade Center during the "Runyon Up," a stair race in which participants run up 72 floors of stairs inside the Four World Trade Center building on April 3, 2014 in New York City.
One World Trade Center nears completion
One World Trade Center is seen through low hanging clouds May 10, 2014 in New York City.
One World Trade Center nears completion
Construction cranes, center, work above the rising structure of One World Trade Center, Monday, June 14, 2010 in New York.
One World Trade Center nears completion
One World Trade Center, center right, towers above the lower Manhattan skyline and the East River, Aug. 14, 2013 in New York.
One World Trade Center nears completion
A construction worker takes in the view from the communication rings on top of One World Trade Center in New York, Aug. 26, 2014.
One World Trade Center nears completion
An ironworker carries a piece of steel at the World Trade Center construction site in New York, July 29, 2008.
One World Trade Center nears completion
The moon is seen in its waxing gibbous stage as it rises over Lower Manhattan, including One World Trade Center, center, seen from The Heights neighborhood of Jersey City, N.J., Saturday, June 22, 2013.
One World Trade Center nears completion
A tourist takes photos from the Brooklyn Bridge of a test of the Tribute in Light rising from the lower Manhattan skyline in New York, Sept. 5, 2014. The Tribute in Light is an art installation produced annually in remembrance of the attacks of Sept. 11, 2001. It will be turned on again this Sept. 11, the thirteenth anniversary of the attacks.
One World Trade Center nears completion
One World Trade Center is reflected in windows on 4 World Trade Center, Aug. 15, 2013 in New York.
One World Trade Center nears completion
Workers pour the concrete roof of One World Trade Center, Tuesday, Dec. 11, 2012, in New York. Behind them is the steel superstructure that will support a 408-foot spire that is expected to rise into the Manhattan sky by spring.
One World Trade Center nears completion
The final piece of the spire is hoisted to the roof of One World Trade Center May 2, 2013, in New York.
One World Trade Center nears completion
One World Trade Center, seen from a helicopter looking directly down on the building, is seen on November 12, 2013 in New York City. The building was deemed the tallest building in North America today; the title was previously held by Willis Tower in Chicago (previously titled Sears Tower).
One World Trade Center nears completion
Workers walk past a video art installation in the lobby of 4 World Trade Center in New York, Nov. 7, 2013.
One World Trade Center nears completion
A security camera hangs from the side of One World Trade Center, Friday, Aug. 8, 2014, in New York. Next month will mark the 13th anniversary of the attacks of Sept. 11, 2001.
One World Trade Center nears completion
The One World Trade Center building is seen from the 9/11 Memorial site in New York, Sept. 9, 2014.
One World Trade Center nears completion
A view of Manhattan looking north from the One World Observatory site, the planned public observation deck under construction on the 100th floor of One World Trade Center in New York, April 2, 2013.
One World Trade Center nears completion
One World Trade Center, center, rises above waterfalls at the National September 11 Memorial and Museum, Sept. 8, 2013, in New York.
One World Trade Center nears completion
Fireworks launched from Hoboken, N.J., light up the sky over 1 World Trade Center, Sunday, Sept. 7, 2014, in New York. The fireworks display was part of the Hoboken Italian Festival.