意外致死,意外死亡
the official expression used in court for a death that happens by accident
  The coroner recorded a verdict of death by misadventure. 验尸官所作出的鉴定结论是意外致死。 
 The official verdict was death by misadventure.
 At the inquest, the verdict was death by misadventure.
 A verdict of death by misadventure was returned on the 52-year-old teacher from Devon.
 The coroner recorded a verdict of death by misadventure and extended her sympathies to the family.
 See also: misadventure