 NIST also did not find any evidence that missiles were fired at or hit the towers.Instead, photographs and videos from several angles clearly show that the collapse initiated at the fire and impact floors and that the collapse progressed from the initiating floors downward until the dust clouds obscured the view" and posted a FAQ about related issues on its website in August 2006.Allegations of controlled demolition have been found to be devoid of scientific merit by mainstream engineering scholarship.