Max Cleland is a former US senator who served on the 9/11 commission:

quote from wikipedia:

he was quoted as saying in November 2003: "I... cannot look any American in the eye, especially family members of victims, and say the commission had full access. This investigation is now compromised."[20] He called the 9/11 Commission a "national scandal." [21][22]

On the other hand you have structural engineers and architects and like Richard Gage putting their reputations on the line with peer-reviewed articles on the subject.

Richard Gage was interviewed on CSPAN earlier this month. ...  http://www.youtube.com/watch?v=BtGhjzI9rw4