Actually if you look into it they just set the coal bins on fire... Similar to how they brought down wtc7 why setting office furniture in fire. Little known fact instead of using explosives you can put old office furniture in a steel and concrete building and it will come down at free fall speed. Also the owner of the building can determine when to bring it down by using the term pull it. Pull it is used in controlled demolitions and accidental office fires to bring down buildings at a precise time and all this done during the the biggest terrorist attack in USA history. And it was a jew who owned the buildings leases which he got 6 months prior.