Recent experience in Japan, Mexico, and elsewhere shows that substantial damage, even total collapse, can occur to steel buildings. This project studies the effects of several recently recognized factors on the seismic performance of steel frame systems. These are: interaction of multicomponent ground motions, P-delta effect, and the effect of low ductility members. The study makes use of the established analytical capabilities in seismic analysis of buildings subjected to interacting ground motions at the University of Missouri-Rolla, and the extensive research experience in steel building structures at Lehigh University. The collaboration should provide a unique opportunity to develop an improved understanding of the seismic performance of tall steel buildings and more reliable methods of evaluating safety of such structures. The results would be useful for practicing engineers, academic researchers, and code writing bodies.