Ground Zero Smoking Gun #1
from here. (double click to enlarge)
I don't know quite how they did this, but somehow they tilted this huge section of WTC1 wall so it fell UP the street rather than fall accross the street and damage the World Financial Center:
(double click to enlarge)
This all goes to the point of how little major collateral damage there was to NON-WTC buildings.
Judy Wood has an amazing picture of this section of wall from the street perspective on this page.
This section was laying right in West Side Highway, ready for trucks to come and haul it away, and was one of the first things they cleaned up-- therefore is not visible in many pics of Ground Zero.