A Wisconsin man and his wife have filed a wrongful death lawsuit against the man's own parents in the death of their young son, reports the Minneapolis Star Tribune. Their five-year-old child was killed in a fire that broke out at his grandparents' house. The grandfather suffered serious burns in the fire, while the grandmother escaped unharmed. According to the Star Tribune, the lawsuit alleges that the grandparents were negligent in extinguishing the fire improperly and in failing to save the child, who was asleep in an upstairs bedroom.