The idea of the Twin Towers came about in the early 1960s by the Downtown-Lower Manhattan Development Association. By 1962, the Port Authority of New York and New Jersey began plans to build the two towers. Minoru Yamasaki was chosen out of a dozen other architects. His plan included twelve million square feet of floor area, which also had to accommodate new facilities for the Hudson tubes and subway connections.
             "After studying more than one hundred schemes in model form, Yamasaki decided on a two-tower development to contain the nine million square feet of office space. One tower became unreasonable in size and unwieldy structurally, yet several towers became too approximate for their size and 'looked too much like a housing project'; whereas two towers gave a reasonable office area on each floor, took advantage of the magnificent views, and allowed a manageable structural system."¹
             Critics claimed that the towers would "Rob New York of character, ruin the skyline, disrupt television reception, and strain city services."² They started construction in 1966.
             The World Trade Center consists of sixteen acres of land. In building of the Twin Towers, five streets were closed off and 164 buildings were destroyed. A total of 10,000 people were involved with the building of the Twin Towers. Sixty people died while in construction.
             The designs for the towers were inventive in several ways which include its elevator system and its structural system. A regular elevator known as the conventional elevator would have taken up half of the room on the lower floors. Otis Elevators developed express elevators which halved the number of shafts needed for the elevators. The "structural system" of the towers used an architecture called the "Tube." Each tower had a structural core extending from the "bedrock bottom" to its roof. The cores were rectangular pillars with columns and girders. The...