Project АС-31, nicknamed Losharik (Russian: Лошарик), is a Russian deep-diving nuclear powered submarine.
A fire broke out on the vessel on 1 July 2019 while it was taking underwater measurements of the sea floor in Russian territorial waters. Fourteen of the crew were killed by inhalation of smoke or toxic fumes. Seven of those who died held the rank of first rank captain and two were recipients of the Hero of the Russian Federation award. Submarine commander Denis Dolonsky was among those killed.
Denis Vladimirovich Dolanski (1972 - 2019) — a Russian submarine officer-gidronavty, commander of deep-sea submarine











