2008_04_freedtower.jpgParties involved with the design and construction of Freedom Tower were happy with tests in the New Mexico desert where a model of the structure was detonated. A partner at architecture firm Skidmore, Owings & Merrill, Carl Galioto, told the Observer, "The specimen performed beautifully, far exceeding our expectations."

Safety has long been an issue with Freedom Tower--when the NYPD felt the design needed work, architect David Childs added a concrete base to the building. The concrete, though, was ugly, so it was redesigned with glass panels over the base. A different model also underwent wind tests in Canada and thermal and water tests in California, as the real Freedom Tower will have "23 acres of glass surface area."

However, the Port Authority, which is building the structure, did not disclose how big a blast was used for the testing, with a Port Authority project executive only saying to the NY Times, "The simple answer is, yes, it passed."

Freedom Tower's foundation was started in 2006. It is expected to be completed by 2012.

Photograph of Freedom tower mock-up from the Port Authority