9/11 changed the National Guard forever, according to four NGAUS staff who were profoundly impacted by that fateful day.
Wednesday marks the 23rd anniversary of the terrorist attacks on Sept. 11, 2001, which killed 2,977 people nationwide.
Nineteen terrorists hijacked four airplanes during the attacks, which crashed in New York City, Arlington, Virginia, and Shanksville, Pennsylvania.
Retired Col. Mike Hadley was in Arlington when one of those airplanes struck the Pentagon over two decades ago.