What idiom is used to describe the Tangshan earthquake?

It can be described as landslide.

7.28 Tangshan earthquake refers to an earthquake of magnitude 7.8 (moment 7.5) on July 28th, 0976 at 3: 42: 53.8 seconds in Fengnan area, Tangshan City, Hebei Province, China (east longitude 1 18.2, north latitude 39.6), with the epicenter intensity of 18. The earthquake killed 242,769 people, and 16485 1 person was seriously injured, ranking second in the history of earthquakes in the world in the 20th century, second only to offshore earthquakes.