Conspiracy theories are often built around anomalies which are difficult to prove either way. The "assumptionists" are convinced they know what the anomaly is. One such anomaly is the so called "Squibs".
They say this anomaly is an explosive charge going off and a sure sign of Controlled Demolition. It's often followed by more video of charges going off in real Controlled Demolitions. But if we examine the anomaly closely, we see these [would be] explosives work in reverse to an explosive blast. They tend to spurt out and then increase with time. An explosive works in reverse to this. Its strongest point is the moment the charge is set off. It doesn't increase its explosive strength with time.
So what is this then? Why would debris jet out of windows far below the collapse?
It could be a number of things, by themselves or in combination. One reasonable explanation is a buildup of pressure caused by the compression of air between the floors as they pancaked, (Please read the link to explain the NIST / Pancaking issue) pushed debris out of the already broken windows and/or open vents. Another is falling debris like elevators or elevator parts/motors and/or columns free falling down the elevator shafts and slamming into lower floors creating debris. In a sense the floors are large plungers and the towers are just one big Syringe during the collapse.
During the pancake, the floors acted like a plunger in a Syringe. The towers skin and windows became the tube of the Syringe. The increased pressure blew the windows out as each massive acre of floor compressed air between them. It's said that the towers were about 95% air. But not all the air went so easily out the window space. There was just as much window as there was steel perimeter columns. So the air takes the path of least resistance to the core. The core is collapsing and thick debris is preventing the air from going up. Its next path of least resistance would be to go down the core. The air pushed though the core any way it could and the pressure built up. It forced its way out on lower floors wherever it could. According to the survivors of at least one tower, a hurricane wind blows through the staircase which is located in the core...
Matt Komorowski: “The first thing I really felt was the incredible rush of air at my back. And maybe I felt it before everybody else, because I was the last guy.”
Stone Phillips: “Like a gust of wind, behind you.”
Matt Komorowski: “Gust of wind. Wind tunnel. It was the most incredible push at your back, that you can feel.”
http://www.acfd.com/miracle_of_ladder_company_6.htm