On 9/11, the FBI believed that bombs were involved in the attacks.
How do I know that?
Because, according to the FBI's website:
Following the massive terrorist attacks against New York and Washington, the FBI dedicated 7,000 of its 11,000 Special Agents and thousands of FBI support personnel to the PENTTBOM investigation. "PENTTBOM" is short for Pentagon, Twin Towers Bombing.
Indeed, a reporter for USA Today was told by the FBI believed that there were bombs in the Twin Towers.
Similarly, the Washington Post believed that bombs were involved, as reflected in a September 21, 2001 article containing the following phrase:
In the hours after Tuesday's bombings . . . .
Many firefighters and policemen also said there were bombs in the Twin Towers.
And perhaps "the premiere collapse expert in the country", who 9/11 Commissioner Timothy Roemer referred to as a "very, very respected expert on building collapse", the head of the New York Fire Department's Special Operations Command and the most highly decorated firefighter in its NYFD history, who had previously "commanded rescue operations at many difficult and complex disasters, including the Oklahoma City Bombing, the 1993 World Trade Center Bombing, and many natural disasters worldwide" thought that the collapse of the South Tower was caused by bombs, because the collapse of the building was too even to have been caused by anything else (pages 5-6).
But surely experts have since proven that no bombs were involved. Right?
Even the former head of the Fire Science Division of the government agency which claims that the World Trade Centers collapsed due to fire, who is one of the world's leading fire science researchers and safety engineers, a Ph.D. in mechanical engineering (Dr. James Quintiere) doesn't bevelieve an adequate investigation into 9/11 has been conducted. He has called for an independent review of the World Trade Center Twin Tower collapse investigation. "I wish that there would be a peer review of this," he said, referring to the NIST investigation. "I think all the records that NIST has assembled should be archived. I would really like to see someone else take a look at what they've done; both structurally and from a fire point of view. ... I think the official conclusion that NIST arrived at is questionable."