To me, nothing could be less surprising than to learn that small explosions and popping noises emanated from a skyscraper that was hit by an airliner and had massive fires on several floors and smaller fires throughout the elevator shafts and on floors below the impact areas. I can think of many possible causes of such noises, and I implore William Rodriguez and other conspiracists to at least try to consider rational explanations for such phenomena before hopping on board the 9/11 mystery train.“He said there were devices going off all over the building - that he and the firefighters could hear explosions periodically as they climbed.” Source
"As we go up, we hear small explosions going off. Pah! Pah! Different areas. And I said to the firemens, what’s that? And they said – one of them – told me, “I think it’s the gas tanks from the kitchen.” Now that did not make sense, because it was a Class A building. All the kitchens were electrical. All the kitchens were electrical. So that did not make sense. What are those explosions coming from?" Source
“When I was going up I kept hearing more explosions, but there wasn’t any fire like there was in the basement." Source
After hearing numerous small explosions and what he remembers as rapid fire ‘pop, pop, pop sounds” in the mid level floors, as well as strong jolts from the jetliner striking the south tower, Rodriguez then recalls being turned back by a Port Authority officer on the 39th floor.... Source
Here's an excerpt from a report about a fire in another skyscraper, the Madrid Windsor building:
"The fire started around 11:30 p.m. Saturday and was still burning out of control several hours later. At least nine upper stories were on fire and muffled explosions could be heard in the building." Source
What could make the noises that Rodriguez heard? Pockets of fuel igniting. Inflammable liquids and aerosols that were stored in the building igniting. Debris falling down elevator shafts. Windows and marble breaking due to building movement. Structural steel and connections giving way as the building's load is redistributed away from failed and failing elements. Concrete fracturing. Walls cracking. Electrical shorts. Ceiling collapses. Firefighters forcing doors open. These explanations seem plausible to me. Shortly, we will read a quote from Rodriguez about the twisting of the north tower causing damage in the stairwells. He should think about that.
Instead, here's what Rodriguez says about the smoke in the stairwells:
It was an acrid smoke. It was like ammonium stuck into your throat. Spoke to professor (Steven) Jones about it. Spoke to experts who said, you know, ‘sounds like ammonium nitrate.' I mean, I’m not an expert on those things. SourceI'd bet my bottom dollar that William Rodriguez spoke to no experts about this issue. If he had, they likely would have said what dozens of other people said: the acrid smoke came from burning jet fuel, electrical insulation, etc. Ammonium nitrate is used in fuel/fertilizer bombs. I have come across no other descriptions of an ammonia smell in the towers. If Rodriguez is taking Steven E. Jones' suggestion about that, he's making a mistake. When it comes to making sense of 9/11, Jones, a former physics professor at BYU, has proven himself to be either laughably incompetent or an outright fraud. My money is firmly on the latter choice. Examples of Steven Jones' "incompefraud" can be found here and here and here.
One thing to keep in mind is that firefighters searched all the floors that Rodriguez was on and many above. As they were trained to do after a terrorist attack, many of them were wary of the possibility of secondary explosive devices. No evidence of such devices was found on 9/11 or amongst the billions of pounds of debris that was meticulously sorted by NYPD detectives and FBI Evidence Response Teams at Fresh Kills landfill. No sign of explosives or incendiary use was reported by anyone, including the hundreds of ironworkers who became intimately familiar with the steel, nor can any such sign be discerned in any photograph of the ruins.
Another thing to keep in mind (and it's silly that it needs to be said) is that demolitions charges are LOUD and are used when a structure is to be brought down, not long before. When a building is brought down with explosives, it is extensively pre-weakened to minimize the amount of explosives needed. It would take truly staggering amounts of explosives to bring down the towers without pre-weakening them and without lengthy and direct access to bare steel columns for the placement of precision demolition charges. There isn't a single shred of evidence to support the hypothesis that explosives were used in the towers.
Erik O. Ronningen, descending from the 71st floor of the north tower:
"I remember how calm and orderly the descent in the stairwells was… and how smoky… accompanied occasionally with the snapping sounds of tortured pipes and walls stressed beyond endurance." Source
Here's what two people heard in the south tower after it was struck by United flight 175:
Clyde Ebanks, on the 70th floor: "I think now, these popping sounds were coming out of the elevator shafts because of the fireball that was coming down. The popping sounds, I think, were the elevator doors opening up because of the fireball." (Richard Bernstein. Out of the Blue. New York: Times Books, 2002. p. 223)All that's required to gain an understanding of these issues is a mindset that values fact over fantasy.
Eric Levine, on the 25th floor when flight 175 hits: "Am now holding onto our room's door... clinging to it as if my life depended on it... as the building was still swaying violently... I hear and see more "smaller" explosions....electricity was cut off...more debris... broken glasses... air gushing in... ceiling was slowly caving in..." Source