This is maybe the main problem with official versions because the architects explained it in the interviews that due to proximity of airport and air traffic they specifically designed and simulated the event of big plane hit, or many planes hitting building, and all scenarios related including fire. In NYC, it happened before that smaller planes crashed into skyscrapers. Of course, there are multiple explanations what went wrong (e.g. sprinklers), but again, this building was designed to withstand earthquakes, tsunamis, nukes, wars, etc. It is made of steele bars glued to the bedrock with tonnes of cement.

What happens when aluminium jet crushed into steele beams might look similar to what happens when you cut cheese with cheese cutter, or when you cut a piece of butter with a steele knife, or when you use steele scissors to cut aluminium foil. But, remember, this is all intuition, not science:)