Siglitun, is the dialect of Inuvialuktun spoken by the Siglit Inuit. It is mainly used in the Inuvialuit communities of Paulatuk, Sachs Harbour and Tuktoyaktuk. Siglitun was once the principal dialect of the Mackenzie River delta, nearby parts of the coast and Arctic Ocean islands, but the number of speakers fell dramatically following outbreaks of new diseases in the 19th century and for many years Siglitun was believed to be completely extinct.