25 years after 9/11, the WTC's final office tower is rising; it's a 55-story, 1,226-foot building

(Photo: American Express) Twenty-five years after the September 11, 2001, terrorist attacks destroyed Lower Manhattan's skyline, construction has begun on the final commercial office tower planned for the 16-acre World Trade Center site. The 55-storey, 1,226-foot supertall tower at 200 Greenwich Street, known as 2 World Trade Center, will become the global headquarters of financial services company American Express. The company has agreed to become the building's sole tenant. The nearly two-million-square-foot tower is expected to be fully occupied by 2031. Developed by Silverstein Properties on land owned by the Port Authority of New York and New Jersey, the project brings progress to a part of the site that remained largely at foundation level for nearly 15 years because of planning and financing delays. According to reporting by The New York Post, state filings and announcements from American Express and Silverstein Properties, the tower is the final major commercial building in architect Daniel Libeskind's post-9/11 master plan for the World Trade Center site.Modern design replaces long-delayed foundationBritish architecture firm Foster + Partners designed the tower with a seri...