Never-before-seen images of 9/11 attacks

Close-ups of collapsing upper floors, thick plumes of smoke

New aerial photos of the collapse of the World Trade Center have been released, reports the National Post, who hosts a web gallery of the images. The photos were originally obtained by ABC News via a Freedom of Information Act request filed with the National Institute of Standards and Technology last year. The images were part of an investigation by the NIST, and taken by an NYC Police Aviation Unit.

National Post