Locally generated tsunamis due to faulting or slope failures offshore southern California threaten nearby coastal cities. Disruption of operations at port facilities due to tsunami attack could severely impact the regional and national economies. This study examines three faults and two landslides scenarios as potential tsunami sources. Computed runup ranges from 0.5 to 6 m depending on the source and location. Bathymetric features such as the broad San Pedro Shelf are shown to contribute to tsunami wave focusing while retarding tsunami arrival times, suggesting the usefulness of an early warning system.