Prefabrication for the Twin Towers
Video duration: 1:32
As the World Trade Center towers began to rise, another innovation made its appearance. Unlike earlier skyscrapers, assembled one column or beam at a time, the twin towers were erected in huge prefabricated components. Exterior wall sections three stories tall and floor decks 60 feet long could be lifted into place at once. The daring new technique dramatically speeded the construction process.