NEW YORK— Crane operators hoisted the final pieces of the spire atop One World Trade Center on Thursday, helping to fill the void in the New York City skyline left by the attacks of Sept. 11, 2001.
Once a beacon is installed, the tower will stand 1,776 feet (541 meters) high, making it the tallest building in the Western Hemisphere, though still well shy of the world's tallest structure.
Ironworkers will finish installing the spire, which weighs about 800 tons (725 metric tons) and is 400 feet (122 meters) tall, at a later date.
The tower is one of four skyscrapers designed to rise around the footprints of the fallen Twin Towers in a partnership between developer Larry Silverstein and the Port Authority of New York and New Jersey, which owns the site.
The footprints of the fallen towers have been turned into a memorial to the nearly 3,000 people killed in the 2001 attacks by al Qaeda hijackers.
One World Trade Center, formerly called the Freedom Tower, is estimated to have cost more than $3 billion and is due to open next year. It will have three million square feet (278,000 square meters) of office space, an observation deck, shops and restaurants.
One World Trade Center will eclipse what has been the tallest building in the Western Hemisphere - Chicago's Willis Tower, which stands at 1,451 feet - but will be no rival for the world's record holder.
The tallest building in the world is Dubai's Burj Khalifa, completed at 2,717 feet (828 meters).
One World Trade Center ranks seventh on a list of the world's tallest buildings under construction, according to Emporis, a database for building information.
The tallest would be the Kingdom Tower under construction in Jeddah, Saudi Arabia, at more than 3,280 feet (1 km), or nearly twice the height of One World Trade Center.
Four other buildings under construction in China and one in South Korea would be taller than One World Trade Center, according to Emporis.