Natural disturbances, such as tornados, can alter local habitat conditions and have the potential to affect animal communities in preserves. When such disturbances occur in natural areas, understanding these effects can help land managers develop responses and restoration actions following a disturbance. The effects of tornado and other strong wind damage on insect communities is poorly known even though insects comprise the majority of macroscopic diversity in terrestrial systems and are important contributors to ecosystem function. We examined ground beetle (Coleoptera: Carabidae) communities in spring, summer, and fall following an EF-4 tornado that struck a forested preserve in Illinois. We compared the communities and vegetation structure in plots that were affected or unaffected by the tornado. Sites within the tornado's path had reduced canopy cover but increased ground-level vegetation throughout the growing season. Beetle abundance and species richness were unaffected, but Shannon diversity was significantly higher in fall in areas affected by the tornado. Beetle community composition was shifted by tornado effects only in the spring, and tornado-affected areas contained 13 species that were not present in unaffected sites. These sites also contained more seed-eating or omnivorous species and small predators, in contrast to unaffected sites that were dominated by large predatory species. Our results indicate that tornado damage may increase biodiversity in small natural areas by increasing habitat heterogeneity. Land managers may not want to restore tornado-damaged sites to pre-disturbance conditions if maximizing biodiversity is a goal of the preserve.