A man takes photos in front of a memorial wall for victims of the Tangshan Earthquake in Tangshan, north China's Hebei Province, July 28, 2018. A 7.8-magnitude earthquake struck here on July 28, 1976 and claimed the lives of more than 240,000 people. (Xinhua/Dong Jun)

People mourn for the deceased in front of a memorial wall for victims of the Tangshan Earthquake in Tangshan, north China's Hebei Province, July 28, 2018. A 7.8-magnitude earthquake struck here on July 28, 1976 and claimed the lives of more than 240,000 people. (Xinhua/Dong Jun)

People mourn for the deceased in front of a memorial wall for victims of the Tangshan Earthquake in Tangshan, north China's Hebei Province, July 28, 2018. A 7.8-magnitude earthquake struck here on July 28, 1976 and claimed the lives of more than 240,000 people. (Xinhua/Dong Jun)

People mourn for the deceased in front of a memorial wall for victims of the Tangshan Earthquake in Tangshan, north China's Hebei Province, July 28, 2018. A 7.8-magnitude earthquake struck here on July 28, 1976 and claimed the lives of more than 240,000 people. (Xinhua/Dong Jun)