Accidental death from postural or positional asphyxia can occur when an individual’s body compromises their respiration. The diagnosis of positional asphyxia is usually based on circumstantial evidence supported by the absence of other significant underlying causes of death. A female in her twenties was found dead in the so-called bridge position on a chair with wheels. Her jacket had rolled under one of the chair’s wheels. She was 159 cm in height and weighed 28.8 kg. Her body mass index was 11.4 (she was severely emaciated), and her muscles, including the rectus abdominis muscle, were thin. Her head, face, and neck were markedly congested. Her lungs, especially the upper lobes, were also congested. A small quantity of left cardiac blood was detected, which was slightly coagulated. The right cardiac blood was liquid (21 ml), and the right ventricle was slightly enlarged. It was suggested that the circulation from the lungs to the heart had been restricted. Toxicological tests detected psychoactive agents in the deceased’s blood and urine. The concentration of one of them, tofisopam, was slightly higher than normal. It was suggested that the effects of tofisopam and the deceased’s poor physical condition had impaired her motility, trapping her in an abnormal body position, ‘the reverse jack-knife position’. Therefore, her manner of death was considered to be accidental positional asphyxia. We should be aware that chairs with wheels can occasionally cause such accidents