An 11-year-old boy who was overcome by fumes at a western Minnesota grain silo has died, becoming the third victim to die from the farm accident that also claimed the lives of his father and uncle, authorities said.

Alex Boesl was pronounced dead on Friday, according to the Douglas County Sheriff's Office. The boy had been hospitalized at Children's Hospital of Minneapolis since breathing in the silage gas last Saturday.

The boy's father, 47-year-old Curt Boesl, and uncle, 49-year-old Steven Boesl, also died.

Authorities say Curt Boesl and his son Alex were working on top of the silo near Millerville on Dec. 21 when they apparently were overcome by fumes. Steven Boesl tried to rescue his brother and nephew and also was overcome.

By the time deputies arrived, all three were unconscious. Emergency responders removed the three from the silo.

Ambulance personnel declared Steven Boesl dead at the scene. Curt Boesl died Sunday morning.

Community members in Millerville, a town of about 100 residents, have rallied around the Boesl families. A GoFundMe fundraiser set up to be split between the two families had raised more than $78,000 as of Saturday afternoon.

A funeral Mass for all three victims will take place on Tuesday; funeral arrangements can be found here.