Conspiracy theories on plasco: fire or explosion?

The collapse of the Plasco mall in Tehran caused some people questioning the real reason for the incident. Looking at one of the videos showing the moment of the collapse, some people want to believe that an explosion has taken place. Some think that ISIS was behind it, others accuse the Revolutionary Guard. Similar conspiracy theories were brought up after 9/11. Also in the U.S. some people claimed that explosions had brought the Twin Towers down. But experts have denounced such theories and assured that no explosive traces were found in the debris.