I could be mistaken, but I believe that photographer was killed on 9/11. Their camera was recovered, and the photos developed, however.
It is an incredible photograph. Note all the fine particles of debris - clear sign of a very fast shutter speed. You don't normally see that in video footage because the exposure time for each frame is too long, thus tiny particles like that just blur into the sky and vanish.
Using a very high electronic shutter speed (on a video camera) or a narrow shutter angle (on a film camera) captures sharper details like small pieces of dirt and debris, and produces the distinct "strobing" effect that was used most distinctly in works like "Saving Private Ryan", "Band of Brothers", "Gladiator", and "Black Hawk Down".
-Andrew