Can cause major damage to poorly constructed buildings over small regions. At most slight damage to well-designed buildings. Casualties range from none to a fwe. Can be destructive in areas up to about 100 miles across in populated areas. Death toll ranges from none to 25,000. Can cause serios damage over large areas. Death toll from none to 250,000. Can couse serios damage in areas several hunder miles across. Building structures collapse - skyscrapers at SERIOS risk. Death toll ranges from 1,000 to 1 million. Can cause near or total destruction. Heavy damage and shaking extends to distant locations. Death toll usally over50,000.