[Medico-legal studies on the deaths from coal-mine accidents. 3. Causes of death (author's transl)].

Thirty-four deceased who were killed from twenty cases of coal-mine accidents during fourteen years from 1965 to 1978 were autopsied in our laboratory and their causes of death have been discussed. In the explosion of methane gas and coal dust chemical energy stored in coal or methane is converted to mechanical energy and thermal energy which act upon the human bodies to bring about seven sorts of causes of death. Deaths are caused more frequently by thermal energy directly or indirectly than by mechanical energy. It is a characteristic found in the explosions of coal mines which are large and closed underground spaces consisting of inflammable material. In gas spurt major cause of death is asphyxia from the lack of oxygen resulting from the substitution of air by methane gas and the effects of mechanical energy developed by gas spurt is slight in degree. In the coal-mine accidents the causes of death are so much concurred that is is difficult to certify the cause of death. A new concept of a cause of death has been proposed to solve such a problem.