One World Trade Center, the tallest building in the western hemisphere and a famous modern landmark, is engineered to be the safest and strongest skyscraper ever built. This episode follows the final year of exterior construction, culminating with the milestone of reaching the symbolic height of 1,776 feet. For head of construction Steve Plate, as well as scientists, engineers, ironworkers and curtain wall installers, this is a construction job suffused with the history of the site and a sense of duty to rebuild from the ashes of Ground Zero.