The original 1 World Trade Center (also known as the North Tower, Tower 1, Building One, or 1 WTC) was one of the Twin Towers of the original World Trade Center in New York City. It was completed in 1972, stood at a height of , and was the tallest building in the world until 1973, when surpassed by the Sears Tower (now Willis Tower) in Chicago. It was distinguishable from its twin, the original 2 World Trade Center, also known as the South Tower, by the telecommunications antenna on its roof. Including the antenna, the building stood at a total height of 1730ft (527,3m). Other things that made the North Tower distinguishable from its twin was that there was a canopy connected to the North Tower's west facade on street level and there were two small pedestrian walkways that extended from the west and south promenades of Three and Six World Trade Center to the North Tower's north and south facades on plaza level, while the South Tower lacked any of those. The building's address was 1 World Trade Center, and the WTC complex had its own ZIP code (10048) due to its large size. The original World Trade Center was destroyed in the terrorist attacks of September 11, 2001. Struck by American Airlines Flight 11 at 8:46 a.m., the North Tower was the first of the Twin Towers to be hit by a hijacked aircraft, and the second to collapse, at 10:28 a.m. The North Tower stood for 102 minutes after the aircraft impact. Of the 2,977 victims killed in the attacks, around 1,600 were in the North Tower or on the ground. The North Tower was replaced by the present-day One World Trade Center tower, which was opened in November 2014 as the lead building of the redeveloped World Trade Center site. Tenants at the time of the attacks The tenant list below was compiled from the original list provided by CoStar Group (a provider of electronic commercial real estate information), and quoted by CNN. It was sourced by using UnBlinking.com. Cantor Fitzgerald's corporate headquarters were located in 1 World Trade Center. Note: Floor numbers in red were part of American Airlines Flight 11’s impact area on September 11, 2001, with floors trapped by the impact numbered in dark gray . SOURCES: CoStar Group, CNN, and Unblinking. Floor unknown: Alliance Global Finance, Associated Charter Marine, Carreden Group,