The 7.9 Mw Ancash earthquake shakes Peru with a maximum Mercalli intensity of VIII (Severe) and a landslide buries the town of Yungay, Peru. Between 66,794-70,000 were killed and 50,000 were injured.

The 1970 Ancash earthquake (also known as the Great Peruvian earthquake) occurred on 31 May off the coast of Peru in the Pacific Ocean at 15:23:29 local time. Combined with a resultant landslide, it is the most catastrophic natural disaster in the history of Peru. Due to the large amounts of snow and ice included in the landslide that caused an estimate of 66,794 to 70,000 casualties, it is also considered to be the world's deadliest avalanche.