The natural disaster that struck San Francisco in April 1906 was the San Francisco earthquake. Occurring on April 18, the quake registered an estimated magnitude of 7.8 and caused widespread devastation. The tremors smashed buildings and infrastructure, but the destruction was exacerbated by the related fires that erupted throughout the city, consuming large areas and leading to the displacement of thousands of residents. The earthquake resulted in significant loss of life and property, prompting major changes in building codes and emergency response procedures in the United States. It also influenced urban planning and disaster preparedness initiatives for cities across the nation.