I didn’t take this photo, but it is a poignant reminder of that day and a powerful and uplifting symbol of American resilience. It was emailed to me by a friend who worked at the Pentagon in 2001 (and who was blown out of his chair when the plane hit the building). The photo was taken by Photographers Mate First Class (PH1) Michael W. Pendergrass of the U.S. Navy. I always thought the flag was unfurled on September 11, but discovered that it was hung on September 12 and remained there until October 11.
The flag is a garrison flag measuring 20′ by 38′ and is the largest flag authorized for the military. It belonged to the U.S. Army Band who sent it to the Pentagon after the attack. (Source)