Heat treatment of Salmonella typhimurium results in cell death, which coincides with a significant reduction of the cellular content of 16S ribosomal RNA. It is suggested that the degradation of ribosomal RNA is a direct cause of cell death. This conclusion is based on the observation of carbon-starved and magnesium-supplemented cells, which survive heat treatment much better, and which also maintain stable levels of ribosomal RNA.