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WTC Twin Towers, 1973-2001

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Structure of the New York World Trade Center Twin Towers
Aluminum and steel lattice formed the facade of the New York World Trade Center.

Aluminum and steel lattice formed the facade of the New York World Trade Center. This black and white photo was taken in 1982. Two of the beams were salvaged to be placed in the National 9/11 Museum.

Photo © Daniel Stein / iStockPhoto

The World Trade Center site consisted of seven buildings:

  • WTC 1, the North Tower, had 110 floors
  • WTC 2, the South Tower, had 110 floors
  • WTC 3, a 22 floor hotel
  • WTC 4, the South Plaza Building, had 9 floors
  • WTC 5, the North Plaza Building, had 9 floors
  • WTC 6, the United States Customs House, had 8 floors
  • WTC 7, 47 Floors

On September 11, 2001, terrorists used aircraft to destroy the two tallest buildings.

About the Twin Towers, Designed by Minoru Yamasaki:

  • Tower One was 1,368 feet (414 meters) tall, 110 stories high
  • Tower Two was 1,362 feet (412 meters) tall, 110 stories high
  • Each Tower was 64 meters square
  • Each Tower rested on solid bedrock, the foundations extending 70 feet (21 meters) below grade
  • Height-to-width ratio of 6.8
  • Facades constructed of aluminum and steel lattice
  • Built of a lightweight tube construction with 244 closely spaced columns on the outer walls; no interior columns in office spaces
  • A 80 centimeter tall web joist connected the core to the perimeter at each floor
  • Concrete slabs were poured over the web joists to form the floors
  • Each Tower contained 104 passenger elevators
  • Each Tower had 21,800 windows, over 600,000 square feet of glass
  • Both Towers weighed about 1,500,000 tons together
  • About 50,000 people worked in the Twin Towers
  • Constructed between 1966 and 1973; 3,500 people worked at the site during peak construction; 60 people died during construction
  • Each year, 250,000 gallons of paint were used to maintain the the Towers
  • On August 7, 1974 Philippe Petit used a bow and arrow to assemble a steel cable between the two towers and then he walked across the tightrope. Other stunts included parachuting from the top and climbing from the bottom of the Towers.
  • Almost the same number of murders (19) were committed at the WTC as babies born there (17)

The Twin Towers and the New World Trade Center

After the September 11 terrorist attacks, two trident (3-pronged) columns from the Twin Towers were salvaged from the ruins to be incorporated into the design of the National 9/11 Museum at Ground Zero.

Architects also paid homage to the the lost Twin Towers by giving the new skyscraper, One World Trade Center, similar dimensions. Measuring 200 feet square, the footprint of One World Trade Center matches each of the Twin Towers. Excepting for the spire, One World Trade Center is 1,368 feet tall, like Tower One. If you also exclude the parapet, One World Trade Center is 1,362 feet tall, like Tower Two.

Next: Architect Minoru Yamasaki Discusses the World Trade Center Towers >

Source in Part: The World Trade Center Facts and Figures, Office of Cultural Education, New York State Education Department (NYSED) [accessed September 8, 2013]

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