Though it has been 16 years, Americans who lived through the September 11, 2001 terrorist attacks remember the events of the tragic day vividly. Early that morning, 19 members of the Islamic extremist organization Al Qaeda, split into four teams, each with an experienced pilot, and hijacked four commercial flights — United Flight 93 from New Jersey, American Flight 77 from Washington DC, as well as United Flight 175 and American Flight 11 from Boston.