Katia Krafft (Mulhouse, 17 April 1942 -- 3 June 1991) and her husband, Maurice Krafft (Guebwiller, 25 March 1946 -- 3 June 1991) were French volcanologists who died in a pyroclastic flow on Mount Unzen, in Japan, on June 3, 1991. The Kraffts were known for being pioneers in filming, photographing and recording volcanoes, often getting within feet of lava flows.