WTC Building exploding into fine dust (it is not burning down) by pre-planted explosives in an obvious controlled demolition.
The arrow points to a "squib" of exploding gas which is commonly seen with controlled demolitions. Some of the "splinters" seen (the only solid objects that did not pulverize into dust) are actually chunks of steel beams that were being exploded upward and laterally. The nicely-sectioned steel beams and girders were soon ordered by New York Mayor Rudy Giuliani to be trucked away and shipped to China – an order that constitutes disturbing a crime scene – which is a federal crime.
I just received the latest PBS (Public Broadcasting System) monthly schedule for September and discovered that PBS's newest documentary, entitled "9/11: Inside the Pentagon" will be broad-casting and the re-broadcasting the program a total of 8 times over the week surrounding 9/11/16!