Tangshan earthquake

At 3:42 in the morning on July 28, 1976, an earthquake of about magnitude 7.6 (published estimates run from 7.5 to 8.0) struck Tangshan, an industrial city of coal mines, steel and ceramics in Hebei province, about 140 kilometers east of Beijing. Most buildings, largely unreinforced brick, collapsed within seconds while residents slept. A powerful aftershock hit later that day. The official toll, announced in 1977, was 242,419 dead and about 164,000 seriously injured, making it one of the deadliest earthquakes of the twentieth century. Some outside estimates are far higher.¹²³

The area had been viewed as a zone of low seismic risk, so the city had been built without earthquake-resistant standards. China's prediction program, begun after the 1966 Xingtai earthquakes, had helped officials order evacuations before a magnitude 7.3 quake at Haicheng in February 1975, but nothing comparable preceded Tangshan. The disaster came in the late Cultural Revolution, during the last months of Mao Zedong's life, and the government declined foreign help, sending the army to dig out survivors and rebuild. Tangshan was rebuilt as a new city to modern standards, and China's building rules for seismic zones were strengthened afterward.²³