Port Authority Building Code = NO CORE. No central columns for elevators and evac stairways. Think about the survivors that survived the collapse. They were in the STAIRWELLS. Watch slo-mo of load distribution as exo skeleton failed at plane entry. Oh yeah, take 5 years of physics. Pentagon = missile; #7 was dropped. 1 & 2 were targeted in the 90's (remember the truck bomb?), because this major vulnerability was obvious in 1/4 mile tall buildings. noW: BACK TO WORK
THanks! i did not find that yet.
nice… sauce? and why not on wikipedia?