Forensic diagnostic approach of peri-volcanic area fatalities: About two cases at piton de la Fournaise

The Piton de la Fournaise, located on the island of Reunion, is a particularly active volcano that gathers many observers during its eruptions. However, this activity, if not supervised, can involve many risks. During the eruption of Piton de la Fournaise in April 2021, two geology students camped in the peri-eruptive zone. They were found dead 48 h later on the surface and were not in the immediate vicinity of a fumarole. The autopsy revealed superficial traumatic injuries, which did not explain the death. Internal examination of both victims showed a nonspecific asphyxia syndrome and hemorrhagic pulmonary edema, with no cause of death identified. Microscopic analysis confirmed the autopsy findings without providing new diagnostic elements. Toxicological analysis revealed abnormally high levels of sulfurous gases (H₂ S and SO₂ ) in the blood and lungs of both victims. The interpretation of all the forensic data allows us to conclude that the death was secondary to volcanic sulfur gas poisoning, despite the atypical context of this event. However, the meteorological conditions of the night of the event may have caused a stagnation of toxic volcanic gases on the ground, with concentrations high enough to cause fatal intoxication in these two persons, although they were not in a confined environment as is usually the case in cases of sulfur poisoning. The dramatic outcome of this event required a rigorous forensic diagnostic approach and reminds us of the need to respect safety conditions in peri-volcanic areas.