earthquake originating off the coast of Chile on May 22, 1960, with a moment magnitude of 9.5. The fault-displacement source of this earthquake, the largest in the world in the 20th century, extended over a distance of about 680 miles (1,100 km) along the southern Chilean coast. The cause was major underthrusting of the Pacific Plate under South America. Casualties included about 5,700 killed and 3,000 injured, and property damage in southern Chile amounted to roughly $550 million. Tsunamis (tsunami) triggered by the faulting caused human fatalities and property destruction in Hawaii, Japan, and the West Coast of the United States.