SAN FRANCISCO CALIFORNIA USA GELATIN PHOTOGRAPH 1906 EARTHQUAKE #3 BLUMBERG PHOTO. With an estimated moment magnitude of 7.9 and a maximum Mercalli intensity of XI (Extreme), it created high-intensity shaking from Eureka on the North Coast to the Salinas Valley, an agricultural region to the south of the San Francisco Bay Area. Devastating fires soon broke out in San Francisco and lasted for several days. More than 3,000 people died and over 80% of the city was destroyed. The event is remembered as the deadliest earthquake in the history of the United States. The death toll remains the greatest loss of life from a natural disaster in California’s history and high on the list of worst American disasters.