So there were a bunch of bombs set to explode when the planes hit the building? But these were not the bombs that brought the building down? That was a different set up bombs?
What was the first set of bombs for? To kill important janitors in the basement? We know that no bomb detonated in the basement because of the people working in the basement were injured, but we'll get back to that in a second.
There are two different types of explosions, supersonic explosions DETONATE and subsonic explosions DEFLAGRATE
An explosion is a rapid increase in volume and release of energy in an extreme manner, usually with the generation of high temperatures and the release of gases. Supersonic explosions created by high explosives are known as detonations and travel via supersonic shock waves. Subsonic explosions are created by low explosives through a slower burning process known as deflagration.
No explosions or fires happened a lower levels before the planes hit. Several happened just after the plane hit.
Conclusion: Fires on the lower levels were caused by the impacts of the planes.
Evidence
We discussed previously, there was a path straight to the basement from the impact floors. A few of elevators in WTC that ran the entire length of the building, I believe two in each building went from bottom to top.
To get the observation deck you took an express elevator all the way to the top. So that was an open elevator shaft. The Windows on the World restaurant was also served by an express elevator. Each building also had a freight elevator that went top to bottom.
There are eyewitness occurs of smelling kerosene below the impacts. One employee who was also a pilot recognized it as A1 Jet fuel. Others recognized it as the same smell from kerosene camping laterns. A lot of them remember kerosene by the elevator shafts. There are witness accounts of a fireball shooting out of the elevators in the lobby and an upper floors.
There are many account of people badly burned in these explosions, but there are not accounts of people having the type of injuries from a high explosive detonation. The CDC refers to this as Primary Blast Injuries
Primary
Unique to HE, results from the impact of the overpressurization wave with
body surfaces. Gas filled structures are most susceptible. Injuries include
- lungs, GI tract, and middle ear
- Blast lung (pulmonary barotrauma)
- TM rupture and middle ear damage
- Abdominal hemorrhage and perforation
- Globe (eye) rupture
- Concussion (TBI without physical signs of head
injury)
Linear shape charges like the kind used in controlled demolition use high explosive that detonate. If a detonation occurred in the WTC Lobby or basements, primary blast injuries would be identified.
The explosions in WTC were not detonations and would be consistent with jet fuel flowing down to lower floors and then exploding. In jet fuel, the Fumes are explosive not the liquid form. So the liquid would have time to flow down before the fume ignited.