how tall were the twin towers in floors
World Trade Center (1973–2001) When completed in 1972, 1 World Trade Center became the tallest building in the world for two years, surpassing the Empire State Building after a 40-year reign. The North Tower stood 1,368 feet (417 m) tall and featured a telecommunications antenna or mast that was added at the top of the roof in 1978 and stood 362 feet (110 m) tall. With the 362-foot (110 m)-tall antenna/mast, the highest point of the North Tower reached 1,730 feet (530 m).[91] Chicago's Sears Tower, finished in May 1973, reached 1,450 feet (440 m) at the rooftop.[93] Throughout their existence, the WTC towers had more floors (at 110) than any other building.[91] This number was not surpassed until the advent of the Burj Khalifa, which opened in 2010.[94][95] Each tower had a total mass of around 500,000 tons.[96]
Burj Al Arab The building opened in December 1999.[18]
World Trade Center (1973–2001) Hat trusses (or "outrigger truss") located from the 107th floor to the top of the buildings were designed to support a tall communication antenna on top of each building.[48] Only 1Â WTC (north tower) actually had an antenna fitted; it was added in 1978.[49] The truss system consisted of six trusses along the long axis of the core and four along the short axis. This truss system allowed some load redistribution between the perimeter and core columns and supported the transmission tower.[48]
World Trade Center (1973–2001) The cleanup and recovery process at the World Trade Center site took eight months, during which the remains of the other buildings were demolished. The World Trade Center complex was rebuilt over more than a decade. The site is being rebuilt with six new skyscrapers, while a memorial to those killed in the attacks and a new rapid transit hub have both opened. One World Trade Center, the tallest building in the United States, is the lead building for the new complex, reaching more than 100 stories upon completion in November 2014.