9/11/ 2001 was one of the darkest days in US history (Credit: NPS.edu)

On September 11, 2022, Americans will mark the 21st anniversary of the deadliest terrorist attacks in US history. The unprovoked act of violence was planned and executed by members of the Islamic extremist organization al-Qaeda. The tragedy resulted in the deaths of 2,977 innocent people and altered life as we knew it forever.