05/26/2012 01:34 pm ET

Maryland Dairy Farm Manure Pit Deaths Ruled Accidental

The man and his two teenage sons found dead in a manure pit at a Maryland dairy farm died accidentally, according to the Office of the Chief Medical Examiner in Baltimore.

Autopsies showed 48-year-old Glen Nolt, of Peach Bottom, Pa., and his sons, 18-year-old Kelvin Nolt and 14-year-old Cleason Nolt died of asphyxiation, the AP is reporting. Authorities say the "multiple injuries" that contributed to Cleason Nolt's death were likely caused "by a large propeller on the end of an auger that circulates the liquid manure" in the 2-million-gallon pit where the three were found, according to The Baltimore Sun.

Glenn Nolt's brother-in-law, Nelson Neuenschwander, told Lancaster Online that the Nolts intended to haul away manure from the pond, to be used for fertilizer:

Arriving at the farm Wednesday afternoon, Glenn Nolt fully expected to be back home later that day to milk the cows, Neuenschwander said. The three Nolts were reported missing Wednesday night when they failed to arrive home.

"They had just gotten there early that afternoon and had begun to set up," Neuenschwander said.

"Then no one knows what happened."

Family members believe the three died when one of the Nolts fell into the pit, and the other two attempted to save him, Glen Nolt's brother Nelson Nolt told Lancaster Online.

According to Glen Nolt's obituary, he was a lifelong farmer with seven children. Funeral services will be held Monday at the Bethel Mennonite Church in Quarryville, Pa.