2001 applied architecture buildingfailures casestudies cityplanning civil congresses disasters engineering engineeringgeology environmentalaspects excavation forensicengineering foundations general loadfactordesign mathematicalmodels mathematics mechanics naturaldisasters reliability(engineering) safetyfactorinengineering september11terroristattacks soilmechanics structuralanalysis(engineering) structuraldesign structuraldynamics structuralengineering structuralfailures structuralframes technology terrorism worldtradecenter(newyork