Excerpts from the U.S. Geological Survey page on the past century’s worst natural disasters:
The planet’s deadliest earthquake of the century, by far, was a magnitude 8.0 that struck Tianjin (formerly Tangshan), China, on July 27, 1976. The official casualty figure issued by the Chinese government was 255,000, but unofficial estimates of the death toll were as high as 655,000.
Bangladesh lost 300,000 people in November 1970 and more than 130,000 in April 1991, from cyclone-induced flooding, and the massive flooding of the Yangtze River in China in 1931 caused more than 3 million deaths from flooding and starvation.