The Six Rules of Photo Shooting 

1- Simplicity

Shows only the doomed man falling and the tower, nothing else. 

2- The Rule of Thirds 

After both towers were hit, the photo was taken displays the rule of thirds with the tower as the object in thrids. 

3- Lines

The main lines in this picture are the tower's borders coming down.

4- Balance

The Balance of the columns in the light creates a even balance.

5- Framing

The row of buildings make an artificial frame for the man on ground zero.  

6- Avoiding Mergers

The road, sign, and long line of people are all cut off in this bad crop.