Reply #57: Isn't it asymmetric?

[Carefulplease]

The towers each have two planes of symmetry dividing each floor in four quadrants. Damage close to one corner would produce asymmetric loads unless some similar damage was produced to all other three corners. Symmetry with respect to the core axis would require similar damage to the diagonally opposed corner. The fuel did not produce much structural damage.

The post-impact loads are analysed in the NIST report.