Installation of new beam puts One World Trade Center back at the top of New York's skyline.
One World Trade Center is officially the tallest building in New York City.
Construction crews erected steel columns to form a girder that will eventually become the 100th
floor of the building on Monday.
The structure now stands a little more than 1,250 feet tall, topping the Empire State Building.
Upon completion one world trade will stand a symbolic 1,776 feet, becoming the tallest building in the United States and the second tallest in the world behind the Burj Khalifa Building in Dubai.