An unusual occupational accident: fall into a sewage plant tank with lethal outcome

Occupational accidents, often presenting with lethal outcomes, are a rarely reported issue in forensic literature. However, these incidents are part of medicolegal casework with special regard to reconstruction, liabilities and insurance law-related issues, respectively. We report on a lethal occupational accident in a metropolitan sewage plant. When performing routine controls, a technician fell into an overflow sewer and was immediately pulled into a 30 cm diameter drain. Rescue efforts were initiated immediately, but had to be terminated due to gas warning. Rescue teams continued the search, however, the body remained undiscoverable. Forty-eight hours later, the cadaver was found in an adjacent digester tank, from where it was finally rescued. It was concluded, that the body had been transported between the overflow sewer and the digester tank through a 120 m pipeline with several 90° bendings and branch connections with a minimum diameter of 25 cm at the discharge valve. On medicolegal examination, the cadaver showed marked signs of advanced decomposition caused by anaerobic microorganisms in the 37° C biomass environment. Moreover, as a consequence of the passage of the pipeline system, signs of massive trauma (several comminuted and compound fractures) were disclosed at autopsy. To us, this is the first report on a lethal occupational accident in a sewage plant; our observations demonstrate the rapid progress of putrefaction in a warm anaerobic bacterial environment and the massive trauma sustained.