Huayna Capac dies, possibly from smallpox (an epidemic had been tearing through the New World immediately after its introduction by the Spanish). Catastrophically, Huayna Capac had failed to name an heir before his death. The ensuing power struggle between his two sons, Huáscar and Atahualpa, eventually leads to a civil war. Huascar assumes the throne supported by the nobility in Cusco. Meanwhile Atahualpa, who was considered a more capable administrator and warrior, is crowned Sapa Inca in Quito. It is unknown how many Inca were killed or died during the civil war. The estimated population of the Inca empire before an epidemic (probably of a European disease) and the Spanish conquest is estimated at between 6 and 14 million people. The civil war, an epidemic, and the Spanish conquest resulted in a population decline over several decades estimated as 20:1 or 25:1, meaning that the population declined by 95 percent.