Windows on the World was a complex of venues on the top floors (106th and 107th) of the North Tower (Building One) of the original World Trade Center complex in Lower Manhattan that included a restaurant called Windows on the World, it operated until 2001 when they were destroyed in the September 11 attacks (also referred to as 9/11) were a series of four coordinated terrorist attacks by the Islamic terrorist group al-Qaeda on which country?
September 11 attacks The September 11 attacks (also referred to as 9/11) were a series of four coordinated terrorist attacks by the Islamic terrorist group al-Qaeda on the United States on the morning of Tuesday, September 11, 2001. The attacks killed 2,996 people, injured over 6,000 others, and caused at least $10 billion in infrastructure and property damage. 
World Trade Center cross The World Trade Center cross, also known as the Ground Zero cross, is a group of steel beams found among the debris of the World Trade Center site in Lower Manhattan, New York City, following the September 11 attacks in 2001. This set of beams is so named because it resembles the proportions of a Christian cross.