Image copyright property of NYC Police Aviation Unit
One of the most dramatic events happened on Sept 11, 2001 with the collapse of the World Trade Center twin towers, forever changing international relations and sparking off a series of conflicts and terrorism acts. The intense drama and rivers of human emotions ran deep, and scores of photojournalists documented the aftermath through their lenses. However, one of the most dramatic photo documentation was captured not by a photojournalist, but by a police detective high up in the sky.
NYPD Detective Greg Sermendinger was in a police helicopter hovering above, and in what's probably the world's most haunting aerial photos, he captured the city of New York being engulfed in a plume of dust when the tower collapsed. These images were classified until recently, and they were immensely useful to the investigations of the towers' collapse.
See the series of images at http://abcnews.go.com/Politics/slideshow?id=9763032