If your sump pump fails during a storm or flood, it's crucial to act quickly to minimize water damage. First, turn off electrical power to the sump pump to avoid safety hazards. Then, consider using a backup sump pump system if you have one installed. If not, contact a professional sump pump service immediately for repairs. Additionally, you may need to remove water manually using a pump or wet vacuum and take steps to address any flooding or water infiltration in your basement or crawl space.