Today marks the 13th anniversary of the September 11 terrorist attacks, and although the 16-acre World Trade Center complex is far from complete, a substantial amount has been rebuilt, filling a long-empty piece of Downtown. "We all wish we could have gotten it done faster," said World Trade Center developer Larry Silverstein this week, "but that does not diminish the pride we all should feel." The 9/11 Memorial has now welcomed visitors for three years, the first tenants will soon move into 4 World Trade Center, and the crown jewel of it all, the 1,776-foot One World Trade Center will finally open its this fall.
One World Trade Center [ ] [ ] Located on the site of what was 6 World Trade Center, this $3.9 billion tower is the centerpiece of the new World Trade Center. The 104-story, three-million-square-foot skyscraper, designed by David Childs of Skidmore, Owings & Merrill, officially rises to 1,776 feet (roof is 1,368 feet), and it was declared the tallest building in the U.S. by the Council on Tall Buildings and Urban Habitat, topping Chicago's Sears Willis Tower. Port Authority Vice Chairman Scott Rechler said Tuesday that it will open this November with a 60 percent occupancy. Conde Nast is the anchor tenant with 1.1 million square feet, and other tenants include Servcorp, KiDS Creative, BMB Group, and Legends Hospitality. A three-level public observation deck on floors 100 to 102, approximately 1,250 feet up, will open sometime next year.

Source: http://ny.curbed.com/archives/2014/09/11/the_status_of_the_world_trade_center_complex_13_years_later.php