The World Trade Center was constructed on September 11.
The Twin Towers of the World Trade Center collapsed on September 11 , 2001 , as a result of being struck by two jet airliners hijacked by 10 terrorists affiliated with al-Qaeda , during the September 11 attacks . The World Trade Center is a partially completed complex of buildings under construction in Lower Manhattan , New York City , U.S. , replacing an original complex of seven buildings with the same name on the same site that were damaged or destroyed in the September 11 attacks .