The September 11 attacks were a series of four coordinated terrorist attacks by the Islamic terrorist group al-Qaeda against the United States on the Tuesday morning in 2001. Four airliners were used to attack the World Trade Centers and the Pentagon. The attacks killed 2,996 people, and injured over 6,000 others, causing at least $10 billion in infrastructure and property damage. It is reported that over 1,000 people died of 9/11-related cancer and respiratory diseases in the months and years following the attacks. May we never forget.