Mr. Dimitri Khalezov is an important researcher and witness to the 9/11 event. In fact, he was a nuclear intelligence officer in the former Soviet Union. He testifies that WTC 1, 2 and 7 were demolished by three underground thermonuclear devices during the 9/11 event. As a matter of fact, there were large cavities found at ground zero (point of nuclear explosion in all English dictionaries printed prior to 2002) and tens of thousands of first responders and local Manhattan residents have suffered from cancers as a result of exposure to this radiation. Google "Dimitri Khalezov" and visit http://www.911thology.com/ or http://www.911-truth.net/. There are videos and pdf files available for your research. Don't miss them.