On September 11th, 2001, a series of terrorist attacks were carried out against the
United States. Four planes were hijacked by members of the Islamic extremist group al-Qaeda, with two planes crashing into the World Trade Center towers in New
York City, one into the Pentagon in Washington D.C., and the fourth crashing in a field in Pennsylvania after passengers attempted to take control of the plane. The attacks resulted in the deaths of nearly 3,000
people and caused significant damage to both the physical infrastructure and emotional fabric of the country.