The 1556 Shaanxi earthquake, or Huaxian earthquake (simplified Chinese: 华县大地震; traditional Chinese: 華縣大地震; pinyin: Huáxiàn Dàdìzhèn), or Jiajing earthquake (Chinese: 嘉靖大地震; pinyin: Jiājìng Dàdìzhèn), is the deadliest earthquake in recorded history. According to imperial records, approximately 830,000 people lost their lives.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. Buildings were damaged slightly in the cities of Beijing, Chengdu and Shanghai. An 840-kilometre-wide (520 mi) area was destroyed, and in some counties as much as 60% of the population was killed. Most of the population in the area at the time lived in yaodongs, artificial caves in loess cliffs; these collapsed in great numbers, causing many casualties.