The "Tribute in Light" installation, projected every September 11, creates two vertical columns of light in New York City to represent the Twin Towers in remembrance of the terrorist attacks (Credit: osi.af.mil)

On Wednesday, September 11, 2019, Americans will commemorate the 18th anniversary of one of the most tragic days in modern US history. On September 11, 2001, 19 members of the Islamic extremist organization Al Qaeda conducted a series of brutal, well-orchestrated attacks on American soil. In addition to cutting short the lives of 2,977 innocent people, the tragedy also set in motion events that would change the course of life both in the US and worldwide.