Autopsies have shown that the man and his two teenage sons who were found dead in a manure pit on a dairy farm in Kennedyville, Md., died of asphyxia, Maryland State Police said.
The Office of the Chief Medical Examiner on Friday ruled the deaths of 48-year-old Glen Nolt, of Peach Bottom, Pa., and his sons, 18-year-old Kelvin Nolt and 14-year-old Cleason Nolt, accidental.
The medical examiner also said Cleason Nolt had multiple injuries believed caused by a large propeller at the end of an auger that circulated the liquid manure.
When the three did not return home Wednesday evening, family members became concerned and drove to the farm, police said.
Liquid manure was pumped out of the pit overnight during the search, and the bodies were recovered early Thursday.