Two more ice mummies, a young girl and a boy, were discovered in an archaeological expedition led by Dr. Reinhard and Prof. José Antonio Chávez in October 1995, and they recovered another female mummy on Ampato in December 1997. Volcanic ash from the nearby erupting volcano of Sabancaya induced ice melt in the area. This caused the Incan burial sites to collapse down into a gully or crater where they were soon discovered by Reinhard and his team. Reinhard published a detailed account of the discovery in his 2006 book entitled, The Ice Maiden: Inca Mummies, Mountain Gods, and Sacred Sites in the Andes.