The conspiracy-oriented group Architects and Engineers for 9/11 Truth claims there is lots of evidence the the World Trade Center towers were brought down by a complex sequence of pre-planned demolition charges using a silent yet powerful classified explosive substance capable of precisely cutting steel beams in half and then throwing them hundreds of feet in the air. They call this "nanothermite".
An obvious problem with this theory is the huge fires that burned for an hour before the buildings collapsed. Why didn't the fires set off the nanothermite?
AE911 attempts to answer this in their FAQ, mentioning the ignition of nanothermite in the detailed answer to FAQ #2:
The linked article continues:
So the argument is that the fires were simply not hot enough to ignite the thermite.
The article linked by "identified in the World Trade Center dust" goes on to say:
Hence AE911 is making contradictory claims. They say they found nanothermite in samples of dust that ignites at 430°C, but simultaneously claim that the nanothermite would have survived the fires because it does not ignite at 927°C, more than twice as hot.