13 Years Later, World Trade Center Is Open Again Condé Nast starts moving into America's tallest building today By Newser Editors and Wire Services Posted Nov 3, 2014 6:20 AM CST 29 comments Comments This Oct. 18, 2014, file photo shows One World Trade Center in the background as people gather for a groundbreaking ceremony at the site of the St. Nicholas National Shrine in New York. (Craig Ruttle) (Newser) – Thirteen years after the 9/11 terrorist attacks, the resurrected World Trade Center is again opening for business, marking an emotional milestone for both New Yorkers and the nation. Publishing giant Condé Nast will today start moving into One World Trade Center (aka the Freedom Tower), the 104-story, $3.9 billion skyscraper that dominates the Manhattan skyline. It's America's tallest building and the centerpiece of the 16-acre site where the decimated twin towers once stood. "The New York City skyline is whole again, as One World Trade Center takes its place in Lower Manhattan," says the executive director of the Port Authority of New York and New Jersey, which owns both the building and the World Trade Center site. An observation deck eventually will be open to the public. Condé Nast CEO Chuck Townsend plans to today walk into what Foye calls "the most secure office building in America." Only about 170 of his company's 3,400 employees are moving in for now, filling five floors of the tower, a Condé Nast spokeswoman says; about 3,000 more will arrive by early 2015. The building is 60% leased, with residents including advertising firm Kids Creative, stadium operator Legends Hospitality, and investment adviser BMB Group. From the northeast corner of the site, the tower overlooks the National September 11 Memorial & Museum built in the footprints of the twin towers. One of the managing partners of the firm that produced the final design tells the AP that the high-rise was built with steel-reinforced concrete that makes it as terror attack-proof as possible, going beyond the city's existing building codes to achieve that. "We did it, we finally did it," he says.