The 1906 San Francisco Earthquake

At 5:12 AM on April 18, 1906, a magnitude 7.9 earthquake struck San Francisco along the San Andreas Fault, rupturing the ground for 477 kilometers. The earthquake was devastating, but the fires that followed were apocalyptic: broken gas mains ignited hundreds of fires that merged into a firestorm that burned for three days. Over 80% of the city was destroyed, more than 3,000 people were killed, and 225,000 of the city's 400,000 residents were left homeless. Refugee camps sprang up across the city, and the disaster triggered one of the largest urban reconstruction efforts in American history. The earthquake transformed seismology as a science, led to the first modern building codes, and established the framework for urban disaster response. San Francisco rebuilt itself within a decade — a testament to American resilience and the wealth generated by the California economy. The 1906 earthquake remains the benchmark against which all subsequent American earthquakes are measured.