FBI Believed that Bombs Were Used on 9/11

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.

(see also this and this).

Indeed, the FBI told a reporter for USA Today that FBI agents believed 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:

http://georgewashington2.blogspot.com/2009/02/fbi-believed-that-911-involved-bombs.html