New York's tower of strength: Historic moment as spire is placed on 1,776ft World Trade Center to make it the tallest building in Western Hemisphere By Associated Press and Daily Mail Reporters The silver spire topping One World Trade Center has been fully installed on the building's roof, bringing the iconic structure to its full, symbolic height of 1,776 feet. The spire's installation was completed Friday morning, after pieces of it had been transported to the roof of the building last week. Construction workers below applauded and cheered at the milestone. 'It's a pretty awesome feeling,' Juan Estevez, a construction project manager, 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.' The building is rising at the northwest corner of the site where the twin towers were destroyed in the Sept. 11, 2001, terror attacks. The area is well on its way to reconstruction with the 72-story Four World Trade Center and other buildings. The 408-foot spire, weighing 758 tons, will serve as a world-class broadcast antenna. An LED-powered light emanating from it will be seen from miles away and a beacon will be at the top to ward off aircraft. Stunning: The spire of the World Trade Center has been put in place, allowing the iconic structure to tower over New York City at 1,776 feet What a high: Installation of the spire atop the new One World Trade Center building was completed Friday morning in New York City, breaking records New skyline: One World Trade Center, top center, seen from the Heights neighborhood of Jersey City, New Jersey after the spire was put in place Standout: As the sun rises over New York City on Friday morning, residents will awake to a new skyline after the addition of the spire Breathtaking: The spire for the top of One World Trade Center can be seen as the highest point of New York City as the city awakes The 1,776 feet alludes to the year 1776, when the U.S. declared its independence. Lee Ielpi, whose firefighter son died after responding to the attacks, watched workers secure the spire from his office at the nearby 9/11 Tribute Center, which he co-founded. 'The building looks spectacular,' he said. 'I'm looking forward to the day when the cranes come down and they light the spire at night. It's supposed to be a very moving experience.' Last week, construction director Steven Plate told WABC that the spire will be a 'beacon that'll be seen for miles around and give a tremendous indication to people around the entire region, and the world, that we're back and we're better than ever'. Port Authority Vice Chair Scott Rechler added to the Today show: 'This really is a symbolic moment because this building really represents the resiliency of this country. These people, the thousand men and women who have worked here tirelessly, really as a tribute for the people that perished on 9/11 right on this site. Going up! The silver spire topping One World Trade Center is lifted as it is fully installed on the building's roof early on Friday morning Almost there! The final piece of the spire, draped in an American flag, is hoisted in place on top of One World Trade Center on Friday morning Last moments: Iron workers cheer and whistle out as they watch a crane lift the final piece of the spire to the top of One World Trade Center One last piece: Iron workers watch as a crane lifts the final piece of the spire to the top of the structure, making it the tallest building in the Western hemisphere The tower is slated to open for business in 2014. Tenants will include magazine publisher Conde Nast and the government's General Services Administration. But as crews placed the spire atop the building, a worker was injured after he plunged from an elevated platform and hit his head. He was rushed to hospital, where he is in stable condition. The addition of the spire, and its raising of the building's height to 1,776 feet, would make One World Trade Center the tallest structure in the U.S. and third-tallest in the world, although building experts dispute whether the spire is actually an antenna - a crucial distinction in measuring the building's height. If it didn't have the spire, One World Trade Center would actually be shorter than the Willis Tower in Chicago, which stands at 1,451 feet and currently has the title of tallest building in the U.S., not including its own antennas. The Council on Tall Buildings and Urban Habitat, a Chicago-based organization considered an authority on such records, says an antenna is something simply added to the top of a tower that can be removed. By contrast, a spire is something that is part of the building's architectural design. Height is complicated," said Nathaniel Hollister, a spokesman for The Council on Tall Buildings and Urban Habitats, said. Final touches: Iron workers gather on the roof of One World Trade center to watch as the final piece of spire is hoisted in place Anticipation: Iron workers watch as the spire is placed atop of the structure - before cheering and clapping when it was put in place Historic moment: An iron worker reaches out to touch the final piece of the spire before it is placed on top of the One World Trade Center Taking in the view: An iron worker leans on a safety fence to look at the New York skyline after watching a crane lift the final piece of the spire Towering: The view of the Manhattan, left, and Brooklyn bridges as seen from the 105th floor of One World Trade Center on Friday Capturing history: Iron workers gather for a photograph as the final piece is put on the structure, which has been undergoing construction since 2006 Team: Iron workers pose for photos on the roof of One World Trade center before the final piece of spire is hoisted in place Experts and architects have long disagreed about where to stop measuring super-tall buildings outfitted with masts, spires and antennas that extend far above the roof. Consider the case of the Empire State Building: Measured from the sidewalk to the tip of its needle-like antenna, the granddaddy of all super-tall skyscrapers actually stands 1,454 feet high, well above the mark being surpassed by One World Trade Center on Monday. Purists, though, say antennas shouldn't count when determining building height. An antenna, they say, is more like furniture than a piece of architecture. Like a chair sitting on a rooftop, an antenna can be attached or removed. The Empire State Building didn't even get its distinctive antenna until 1952. The record books, as the argument goes, shouldn't change every time someone installs a new satellite dish. Excluding the antenna brings the Empire State Building's total height to 1,250 feet. That was still high enough to make the skyscraper the world's tallest from 1931 until 1972. From that height, the Empire State seems to tower over the second tallest completed building in New York, the Bank of America Tower. Yet, in many record books, the two skyscrapers are separated by just 50 feet. That's because the tall, thin mast on top of the Bank of America building isn't an antenna, but a decorative spire. Unlike antennas, record-keepers like spires. It's a tradition that harkens back to a time when the tallest buildings in many European cities were cathedrals. Getting ready: Last week, construction workers set off to hoist up the spire, which appears like a tiny speck against the side of the World Trade Center Soaring: The final section of the spire is raised to the top of One World Trade Center The celebration comes just a week after a grisly reminder of the terror attack that took nearly 3,000 lives: the discovery of a rusted piece of airplane landing gear wedged between a nearby mosque and an apartment building - believed to be from one of the hijacked planes that ravaged lower Manhattan. On Wednesday last week, medical examiners concluded their hunt while reporting having found no human remains.