A Case of Dyadic Death Associated with Helium Gas: An Autopsy Case Report

A 39-year-old man, his 35-year-old wife, and their 13-year-old daughter were found dead in their home. The man and his daughter were found lying in her bedroom, with his head wrapped in a plastic bag connected to four helium gas cylinders by green polypropylene tubes. Fragments of the burnt ignition briquette were found in the buck- et located at her feet. His wife was found in a decomposed state lying on her right side in her bedroom. Autopsy findings for the man were unremarkable except for cherry pink lividity; the blood carboxyhemoglobin concentration was 73%. Autopsy findings were unremarkable for the woman as well, except for a few petechial hemorrhages and conjunctival congestion. The daughter showed no definite abnormalities; howev- er, her blood and lung contained helium gas. The deceased man' s suicide note, evi- dence gathered at the scene, and postmortem examination revealed that this was a case of dyadic death.