Hurricanes Katrina and Rita were powerful storms that impacted southern Louisiana and Mississippi during the 2005 hurricane season. In Part I, the authors describe and validate a high-resolution coupled riverine flow, tide, wind, wave, and storm surge model for this region. Herein, the model is used to examine the evolution of these hurricanes in more detail. Synoptic histories show how storm tracks, winds, and waves interacted with the topography, the protruding Mississippi River delta, east-west shorelines, man-made structures, and low-lying marshes to develop and propagate storm surge. Perturbations of the model, in which the waves were not included, show the proportional importance of the wave radiation stress gradient induced setup.