(AP) – Authorities say two brothers are dead after being overcome by fumes in a grain silo on a western Minnesota farm.

The Star Tribune reports the victims were identified as 47-year-old Curt F. Boesl and 49-year-old  Steven T. Boesl. Authorities say an 11-year-old son of Curt Boesl’s, Alex, also fell ill to the fumes late Saturday morning near Millerville and was taken by air ambulance to a Twin Cities hospital.

His condition has not been released. Ambulance personnel declared Steven Boesl dead at the scene. Curt Boesl died Sunday morning.