In his new book, American Conspiracies: Lies, Lies, and More Dirty Lies That the Government Tells Us, former Minnesota Gov. Jesse Ventura begins an investigative journey to prove that there is more to our national history than the government wants us to know. In this excerpt, he writes about an alleged 9/11 cover-up. Chapter 12: What really happened on September 11? Our government engaged in a massive cover-up of what really happened, including its own ties to the hijackers. Unanswered questions remain about how the towers were brought down, and whether a plane really struck the Pentagon. The Bush Administration either knew about the plan and allowed it to proceed, or they had a hand in it themselves. I certainly never expected to think that elements of the Bush Administration were complicit. Today, though, I am convinced that some people inside our government knew the attack was going to happen and allowed it to come to pass - because it furthered their political agenda. I say this after expending many hours researching things about the official story that don't add up, and interviewing a number of witnesses with firsthand knowledge that contradicts what we were told. As a patriotic American, I say this with a heavy heart - and with an outrage that really knows no words. But it's something we, as a nation, must come to terms with. Otherwise, it could happen again.