Death by sewer gas: case report of a double fatality and review of the literature.

Hydrogen sulfide (H2S), the toxic gas associated with the smell of "rotten eggs," is an important cause of work-related sudden death. The gas is particularly insidious due to the unpredictability of its presence and concentration and its neurotoxicity at relatively low concentrations, causing olfactory nerve paralysis and loss of the warning odor. We report a double fatality involving 2 surveyors working near a man-hole, who fell into the sewer and died due to sudden exposure to hydrogen sulfide gas. Key historical, physical, and toxicologic findings are described. Additionally, we present a discussion of the clinical presentations and differential diagnosis, mechanism of injury, metabolism and toxicology, incidence, and scene and safety concerns in fatal hydrogen sulfide exposures.