Construction of the World Trade Center
Video duration: 2:07
The foundations themselves presented the first challenge. They would have to descend through 70 ft. of water-logged landfill before reaching bedrock. The greatest challenge by far, however, lay in the engineering of the towers themselves. The solution, developed by the structural engineers John Skilling & Leslie Robertson in the mid-1960s, was to re-conceive the basic structure of tall buildings.