<Tr> <Th_colspan="2"> References </Th> </Tr> <Tr> <Td_colspan="2"> I. ^ World Trade Center at Emporis </Td> </Tr> <P> The original World Trade Center was a large complex of seven buildings in Lower Manhattan, New York City, United States . It featured the landmark twin towers, which opened on April 4, 1973, and were destroyed in 2001 during the September 11 attacks . At the time of their completion, the "Twin Towers"--the original 1 World Trade Center, at 1,368 feet (417 m); and 2 World Trade Center, at 1,362 feet (415.1 m)--were the tallest buildings in the world . Other buildings in the complex included the Marriott World Trade Center (3 WTC), 4 WTC, 5 WTC, 6 WTC, and 7 WTC . All were built between 1975 and 1985, with a cost of $400 million ($2,300,000,000 in 2014 dollars). The complex was located in New York City's Financial District and contained 13,400,000 square feet (1,240,000 m) of office space . </P> <P> The World Trade Center experienced a fire on February 13, 1975, a bombing on February 26, 1993, and a bank robbery on January 14, 1998 . 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 . </P>

How many square feet were the twin towers