From earliest contact with European and American explorers up until 1830, more than 90% of the Nuu-chah-nulth died as a result of infectious disease epidemics, particularly malaria and smallpox. Europeans and Americans were immune to these endemic diseases but the First Nations had no immunity to them (see Native American disease and epidemics). The high rate of deaths added to the social disruption and cultural turmoil resulting from contact with Westerners. In the early 20th century, the population was estimated at 3,500.