Reply #3: I understand what you are saying, but even you are saying that the columns

[spooked911]

could not have failed all at once-- rather there would be shifting of strain, some elasiticty and plasticity to the columns but eventually they succumb to the strain. Which is what I was saying. It is ludicrous that all the columns would give way at the same time

But since you seem to undewrstand the collapse so well, perhaps you could explain to me the following:

1) when floor 97 collapsed, how many columns were weakened by the fire? Where were they?

2) Did the floor come detached from its bracings before or after the column failure, or did it stay attached to the core and outer columns during the collapse?

3) why did the floor collapse occur symmetrically and why wasn't there a partial collapse on one side first?