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Two World Trade Center, also known by its street address, 200 Greenwich Street, is an unfinished office building at the World Trade Center site in Manhattan, New York City.〔(【引用サイトリンク】title=Two World Trade Center )〕 The tower is under construction and would be the second on the World Trade Center site. The first tower, the former South Tower of the World Trade Center's Twin Towers, was located across Greenwich Street. It was completed in 1971 and was destroyed in the September 11, 2001 attacks. When completed, the tower will be located on the east side of Greenwich Street, across the street from the original location of the Twin Towers, which were destroyed during the September 11, 2001 attacks. The foundation work was completed in 2013, but construction is on hold. ==Original building (1971–2001)== The original building was also known as the South Tower. When completed in 1973, 2 World Trade Center (the South Tower) became the second tallest building in the world. The South Tower's rooftop observation deck was high and its indoor observation deck was high. The World Trade Center towers held the height record only briefly: the Sears Tower in Chicago, finished in , reached at the rooftop.〔(【引用サイトリンク】 url=http://www.willistower.com/propertyprofile.html )〕 Throughout its existence, however, the South Tower had more floors (at 110) than any other building. This number was not surpassed until the advent of the Burj Khalifa, which opened in 2010.〔(【引用サイトリンク】title=Burj Khalifa - The Skyscraper Center )〕 Of the 110 stories, eight were set aside for technical services in mechanical floors (floors 7/8, 41/42, 75/76, and 108/109), which are four two-floor areas that evenly spaced up the building. All the remaining floors were free for open-plan offices. Each floor of the towers had of space for occupancy. The original Two World Trade Center had 95 express and local elevators.〔Ruchelman (1977), p. 11〕 The tower had of office space.〔(The World Trade Center — Facts and Figures ). Nysm.nysed.gov (1993-02-26). Retrieved on 2014-06-23.〕 Initially conceived as a complex dedicated to companies and organizations directly taking part in "world trade", the South Tower, along with 1 World Trade Center (also known as the North Tower) at first failed to attract the expected clientele. During the early years, various governmental organizations became key tenants of the World Trade Center towers including the State of New York. It was not until the 1980s that the city's perilous financial state eased, after which an increasing number of private companies—mostly financial firms tied to Wall Street—became tenants. During the 1990s, approximately 500 companies had offices in the complex including many financial companies such as Morgan Stanley, Aon Corporation, Salomon Brothers and the Port Authority itself. The basement concourse of the World Trade Center included The Mall at the World Trade Center, along with a PATH station. Electrical service to the towers was supplied by Consolidated Edison (ConEd) at 13,800 volts. This service passed through the World Trade Center Primary Distribution Center (PDC) and sent up through the core of the building to electrical substations located on the mechanical floors. The substations stepped down the 13,800 primary voltage to 480/277 volt secondary service, and then further down to 208/120 volt general power and lighting service. The complex also was served by emergency generators located in the sub-levels of the towers and on the roof of 5 WTC. The 110th floor of 1 World Trade Center (the North Tower) housed radio and television transmission equipment; access to the roof of 1 WTC was controlled from the WTC Operations Control Center (OCC) located in the B1 level of 2 WTC. At 9:03 a.m. EDT on September 11, 2001, five terrorists crashed United Airlines Flight 175 into the southern facade of the South Tower. Three buildings in the World Trade Center complex, including 2 WTC, collapsed due to fire-induced structural failure. The light construction and hollow nature of the structures allowed the jet fuel to penetrate far inside the towers, igniting many large fires simultaneously over a wide area of the impacted floors. The fuel from the planes burned at most for a few minutes, but the contents of the buildings burned over the next hour or hour and a half. The fires might not have been as centrally positioned, nor as intense, had traditionally heavy high-rise construction been standing in the way of the aircraft. Debris and fuel would likely have remained mostly outside the buildings or concentrated in more peripheral areas away from the building cores, which would then not have become unique failure points. In this scenario, the towers might have stood far longer, perhaps indefinitely. The fires were hot enough to weaken the columns and cause floors to sag, pulling perimeter columns inward and reducing their ability to support the mass of the building above. The South Tower collapsed at 9:59 a.m. after burning for 56 minutes in the fire caused by the impact of United Airlines Flight 175 and the explosion of its fuel.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Two World Trade Center」の詳細全文を読む スポンサード リンク
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