Twin Tower

The World Trade Center or Twin Tower was a complex in Lower Manhattan whose seven buildings were destroyed in 2001 in the September 11 attacks. The site is currently being rebuilt with six new skyscrapers and a memorial to the casualties of the attacks. The original World Trade Center was designed by Minoru Yamasaki in the early 1960s using a tube-frame structural design for the twin 110-storey towers. In gaining approval for the project, the Port Authority of New York and New Jersey agreed to take over the Hudson & Manhattan Railroad which became the Port Authority Trans-Hudson (PATH). Groundbreaking for the World Trade Center took place on August 5, 1966. The North Tower (1) was completed in December 1970 and the South Tower (2) was finished in July 1971. Construction of the World Trade Center involved excavating a large amount of material which was used in making Battery Park City on the west side of Lower Manhattan. The complex was located in the heart of New York City's downtown financial district and contained 13.4 million square feet (1.24 million m2) of office space. The Windows on the World restaurant was located on the 106th and 107th floors of the North Tower, while the Top of the World observation deck was located on the 107th floor of the South Tower. Other World Trade Center buildings included the Marriott World Trade Center; 6 World Trade Center, which housed the United States Customs; and 7 World Trade Center, which was built in the 1980s. The World Trade Center experienced a fire on February 13, 1975 and a bombing on February 26, 1993. In 1998, the Port Authority decided to privatize the World Trade Center, leasing the buildings to a private company to manage, and awarded the lease to Silverstein Properties in July 2001. On the morning of September 11, 2001, al-Qaeda-affiliated hijackers flew two 767 jets into the complex, one into each tower, in a coordinated suicide attack. After burning for 59 minutes, the South Tower (2) collapsed, followed a half-hour later by the North Tower (1), with the attacks on the World Trade Center resulting in 2,750 deaths. 7 World Trade Center collapsed later in the day and the other buildings, though they didn't collapse, had to be demolished because they were damaged beyond repair. The process of cleanup and recovery at the World Trade Center site took eight months. The first new building at the site was 7 World Trade Center which opened in May 2006. The Lower Manhattan Development Corporation (LMDC), established in November 2001 to oversee the rebuilding process, organized competitions to select a site plan and memorial design. Memory Foundations, designed by Daniel Libeskind, was selected as the master plan, which included the 1,776-foot (541 m) 1 World Trade Center, three office towers along Church Street and a memorial designed by Michael Arad.

Twin Tower at a Glance
Location : New York City
Status : Destroyed
Constructed : 1 WTC: 1966–1972 / 2 WTC: 1966–1973
Destroyed : September 11, 2001
Antenna/Spire : WTC: 1,727 ft (526.3 m)
Roof : 1 WTC: 1,368 ft (417.0 m) / 2 WTC: 1,362 ft (415.0 m)
Top floor : 1 WTC: 1,355 ft (413.0 m) / 2 WTC: 1,348 ft (411.0 m)
Floor count : Both had 110 floors
Floor area : Both had 4,300,000 sq ft (400,000 m2)
Elevator count : Both had 99 elevators
Architect : Minoru Yamasaki & Emery Roth & Sons
Structural Engineer : Leslie E. Robertson Associates
Contractor : Tishman Realty & Construction Company
Owner : Port Authority of New York & New Jersey
(Source: http://en.wikipedia.org/wiki/World_Trade_Center)