Google has unveiled Groundsource, a new artificial intelligence initiative designed to improve natural disaster prediction by leveraging public information to fill critical data gaps. As part of the company's ongoing Crisis Resilience efforts, this innovation specifically addresses the historical lack of high-fidelity data required to predict urban flash floods. While traditional forecasting models could not effectively anticipate these events due to insufficient historical records, Groundsource changes this dynamic by transforming public reports into a comprehensive dataset. The methodology utilizes Google's Gemini AI model to analyze decades of public reports, successfully identifying over 2.6 million historical flood events across more than 150 countries. Following this analysis, the system used Google Maps to define precise geographic boundaries for each incident, creating a specialized dataset dedicated to urban flash floods. Researchers then trained a new predictive model using this data, achieving the ability to forecast flash floods in urban areas up to 24 hours in advance. These new forecasts are now integrated into Google's Flood Hub, a platform that already provides riverine flood warnings to over 2 billion people in more than 150 countries. This addition marks a significant expansion of Google's flood forecasting capabilities, offering communities better preparedness tools before disasters strike. For scientists and partners, the Groundsource dataset serves as a massive, open-source benchmark that can be used to scale impact, particularly in urban regions that previously lacked reliable historical data on flash flooding. Groundsource joins the existing family of geospatial models and datasets within Google Earth AI. Importantly, the same AI-driven approach holds the potential to be applied to other natural disasters, including landslides and heat waves. By converting verified global reports into actionable datasets, the initiative aims to turn past information into a tool for future resilience. The ultimate goal is to move beyond merely analyzing historical events to building a world where no one is caught unprepared by a natural disaster. Through this effort, Google continues its commitment to closing data gaps and enhancing global safety using advanced artificial intelligence.