 The IJN convened a commission three days after the sinking to investigate the loss . It issued its preliminary conclusions on 25 June , well before the investigation of the wreck was completed , and decided that the explosion was the result of a disgruntled seaman . The commission failed to consider the possibility of fire , which historian Mike Williams considers to be a possible cause , as a number of observers noted smoke coming from the vicinity of No. 3 turret . The truth , however , will never be known . 
