The World Trade Center was a seven building complex featuring two twin towers in Lower Manhattan, New York City. The North Tower was completed in 1972 and became the tallest building in the world for two years, standing at 1,368 feet tall. The South Tower was completed in 1973 and became the second tallest building in the world. On any given day, about 50,000 people worked in the towers and another 200,000 passed through as visitors.

It was on this day, September 11, 2001, that the Twin Towers, a symbol of New York City centered in the heart of Wall Street, were destroyed during the worst terrorist attack in U.S. history. Terrorists from the Al-Qaeda hijacked four passenger jets and intentionally crashed two planes into the Twin Towers, resulting in both of the towers collapsing within two hours. The third plane crashed into the Pentagon in Arlington, Virginia and the fourth in a field near Shanksville, Pennsylvania before it could reach Washington, D.C.

Nearly 3,000 people died in the attacks, most being civilian casualties. There was extensive destruction that took until May of 2002 to fully clean-up. Many memorials have been constructed since, including the National September 11 Memorial and Museum, the Pentagon Memorial, and the Flight 93 Memorial.