The sap2000 model gave us a very good estimate. Urich could not have interpolated data if the data did not exist within the model to begin with. It simply wasn't broken out in the way Urich broke it out. What does an article from 1970 have to do with anything? I read an article the other day claiming that a criminal shot at police with a "40mm Glock." Does that mean that Glock actually makes a handgun that shoots golf ball sized ammunition? Besides the questionable validity of your source from 1970, what do you have to say about the claim that the dynamic load exceeds the capacity of the load bearing structure by an order of magnitude? If you disagree, where is your calculation that shows otherwise? If you are using your conservation of momentum method, how exactly do you account for the support structure that remained standing above the plane of collapse? How do you account for exterior wall panels (visible as large sections in free fall outside the footprint of the building) that were removed from the total mass that existed at the plane of collapse?