Karen Johnson writes:

"Why, for example, did Building 7 collapse? It wasn't hit by a plane, as the towers were. The 9/11 Commission Report completely ignores Building 7. The Federal Emergency Management Agency report discounts fire as a cause and concludes that the reasons for the collapse of Building 7 are unknown and require further research. But when FEMA issued this report, it already cleared the site and disposed of the dust and steel (evidence from a crime scene), thus possibly committing a felony and complicating any "further research."