Builders of the tallest office tower under construction at ground zero have set a 70-ton piece of steel into place — the largest column installed yet at the building.
Three more columns are set to go up Thursday, and 24 by the fall at One World Trade Center, also known as the Freedom Tower. The 1,776-foot-tall skyscraper — the symbolic height that signifies the year of U.S. independence — is the largest of five planned to replace the trade center after the Sept. 11, 2001 attacks.
Each steel column — made at a factory in Luxembourg — is about 60 feet long. The columns at the bottom of the tower's foundation are about 35 feet long.
The new columns will bring the building's steel skeleton several stories above street level. The building is set to be finished in 2013.