One World Trade Center to be New York's tallest building
30 April 2012 Last updated at 18:35 BST
One World Trade Center is to overtake the Empire State Building to become New York's tallest building once a steel column is lifted into place on Monday.
The installation of the column on the 100th floor of the skyscraper will make the structure at the site of the 9/11 attacks 1,271ft (387m) high.
About one floor of the building has been erected per week and it will be 1,776ft tall when completed.
ABC News' Bob Woodruff reports.