The 1989 Loma Prieta earthquake was an oblique thrusting event that ruptured a moderately dipping fault that is subparallel to the San Andreas fault. Rupture initiated at 18 km and propagated both updip and bilaterally. Seismic and geodetic studies indicate that rupture terminated between 8 and 5 km depth. We examine the role of the elastic properties of the crust as a mechanism for reducing stress in the upper crust and terminating rupture. We use linear elastic fracture mechanics and the finite element method to model the Loma Prieta fault rupture as a mode II and mode III shear crack in a layered elastic crust. Our analysis shows that a low-stress condition, generated in our models by a change in material properties in the upper crust, is capable of stopping rupture. We also examine the stress condition at the intersection of the San Andreas and Loma Prieta faults to determine the present state of stress and seismic hazard in the region. We find that the Loma Prieta fault in the upper crust is still closer to the point of failure than the San Andreas fault over the same depth. Rupture of the Loma Prieta fault did not increase the seismic hazard of the San Andreas fault within the crustal volume above the Loma Prieta rupture. ¿ American Geophysical Union 1993