This article focuses on an engineering evaluation of the ground motions recorded during the Loma Prieta earthquake. Regression analysis is employed to evaluate the attenuation characteristics of the elastic and inelastic strength demands imposed by rock and alluvium ground motions on bilinear single degree of freedom (SDOF) systems. Several records are used to illustrate the large seismic demands generated by soft soil ground motions. Strength capacities of modern code-designed structures are compared to the strength demands in order to assess the damage potential of the Loma Prieta ground motions. The Cypress structure is used as an example to illustrate the application of simple demand / capacity concepts for an evaluation of structural performance.