The 1556 Shaanxi earthquake (Chinese: 华县大地震; pinyin: Huà xiàn dà dìzhèn) or Jiajing earthquake (Chinese: 嘉靖大地震; pinyin: jiājìng dà dìzhèn) is the deadliest earthquake on record, killing approximately 830,000 people. It occurred on the morning of 23 January 1556 in Shaanxi, during the Ming Dynasty. More than 97 counties in the provinces of Shaanxi, Shanxi, Henan, Gansu, Hebei, Shandong, Hubei, Hunan, Jiangsu and Anhui were affected. An 840-kilometre (520 mi)-wide area was destroyed, and in some counties 60% of the population was killed. Most of the population in the area at the time lived in yaodongs, artificial caves in loess cliffs, many of which collapsed during the catastrophe with great loss of life.