The World Trade Center is a partially completed complex of buildings, under construction, in Lower Manhattan, New York City, United States, replacing an earlier complex of seven buildings with the same name on the same site. The original World Trade Center featured landmark twin towers, which opened on April 4, 1973, and were destroyed in the September 11 attacks of 2001, along with 7 World Trade Center. The other buildings in the complex were severely damaged by the collapse of the twin towers, and their ruins were eventually demolished. The site is being rebuilt with six new skyscrapers, a memorial to those killed in the attacks, and a transportation hub. 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 its completion in November 2014. At the time of their completion, the “Twin Towers” — the original 1 World Trade Center, at ; and 2 World Trade Center — were the tallest buildings in the world. The other buildings in the complex included the Marriott World Trade Center (3 WTC), 4 WTC, 5 WTC, 6 WTC, and 7 WTC. All these buildings were built between 1975 and 1985, with a construction cost of $400 million ($ in 2014 dollars). The complex was located in New York City’s Financial District and contained of office space. The World Trade Center experienced a fire on , 1975, a bombing on , 1993, and a robbery on , 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 . On the morning of September 11, 2001, Al-Qaeda-affiliated hijackers flew two Boeing 767 jets into the complex, beginning with the North Tower at 8:46 AM then the South Tower at 9:03 AM, in a coordinated act of terrorism. After burning for 56 minutes, the South Tower collapsed at 9:59 AM. 29 minutes later, the North Tower collapsed. The attacks on the World Trade Center killed 2,753 people. Falling debris from the towers, combined with fires that the debris initiated in several surrounding buildings, led to the partial or complete collapse of all the other buildings in the complex and caused catastrophic damage to ten other large structures in the surrounding area (including the World Financial Center); three buildings in the World Trade Center complex collapsed due to fire-induced structural failure, and when the North Tower collapsed, debris fell on the nearby 7 World Trade Center building (7 WTC), damaging it and starting fires so that it eventually collapsed. The process of cleaning up and recovery at the World Trade Center site took eight months. Over the following years, plans were created for the reconstruction of the World Trade Center. The Lower Manhattan Development Corporation (LMDC), established in to oversee the rebuilding process, organized competitions to select a site plan and memorial design. Memory Foundations, designed by Daniel Libeskind, was selected as the master plan; however, substantial changes were made to the design. The first new building at the site was the Center, which opened in . The memorial section of the National September 11 Memorial & Museum opened on September 11, 2011 and the museum opened in May 2014. 1 World Trade Center opened on November 3, 2014; the 4 World Trade Center opened on November 13, 2013; the 3 World Trade Center is under construction and expected to open in 2017; , according to an agreement made with Silverstein Properties Inc., the 2 World Trade Center will not be built to its full height until sufficient leasing is established to make the building financially viable; and 5 World Trade Center will be developed by the Port Authority of New York and New Jersey, but, as of February 2014, a schedule was not confirmed.
