7. Gansu Earthquake, China (1920)
This earthquake, which hit 7.8 on the Richter Scale, leveled every building in not one, but two cities, and opened up over 100mi of fault line. The greatest damage, however, was done by the landslides that followed, which buried entire cities and slowed relief efforts. All in all, this quake has been blamed for between 230,000-273,000 deaths, making it the second-deadliest of the 20th century. It was later renamed the Haiyuan Earthquake after the Chinese county where it hit the hardest, killing nearly 60% of the population.