A young employee of a consultancy firm who had been taking wastewater samples in a rendering plant for 15 days died from asphyxia and pulmonary oedema 5 minutes after descending into a manhole 2 m deep and 100 m from the plant. The rescue team measured a hydrogen sulphide concentration of more than 120 ppm, i.e. more than 10 times the threshold allowed by labour legislation for a 15-minute exposure. The public prosecutor’s office will carry out an investigation to determine the causes and exact circumstances of the accident. The investigation is condemned pending the conclusions of the investigations in progress. The establishment did not have an intervention plan (reception, prevention, safety, intervention instructions, etc.) intended for external interveners and in particular no permit or procedure for entering and working in a confined environment. The victim did not have waterproof clothing.