The death toll is now two following a weekend farming accident in western Minnesota.
47-year-old Curt Boesel died Sunday morning, less than a day after his 49-year-old brother Steven died.
Both of them were overcome by toxic fumes during a rescue attempt on top of a farm grain silo in the Douglas County community of Millerville.
The silo is on the Boesel family's dairy farm.
A local fire department official says the family is aware of the toxic fumes that can accumulate inside a silage silo, where grasses ferment.
Curt Boesl's 12-year-old son Alex was also inside the silo and unconscious.
He remains in a Twin Cities hospital.
According to a GoFundMe page for the family, the boy and his father were working on top of the silo, and the man's brother arrived and attempted to rescue both of them.