Let's look at the accounts MacQueen includes of firefighters who use the words "bomb," "explosives," "secondary devices," etc. He lists 31 such accounts. Here's my analysis:
People in the "described something like a bomb” category – 31
Number who did not actually mention anything about bombs, explosions, devices, etc. – 1 (Walter Kowalczyk). I have no idea why MacQueen included Kowalczyk's account, which includes nothing about explosions, sounds like explosions, or any suggestion of explosives or explosive devices. That's truther "scholarship" for you.
Remaining people in "bomb" category – 30
Number who were describing the collapse of a tower – 30
Number who had no idea at the time that what they heard was the collapse of a tower (usually because they were inside another building). – 15
Number who saw the collapse of a tower, at least partially – 7
Number who explained that they knew the sounds were collapses – 2
Number who said they had no idea what was going on during the event – 4
Number who said, as of the interview date, that they thought they'd actually seen or heard explosives – 0
Number who have claimed since 2001 that they believe there were explosives in the buildings – 0