The Olympian reports the wrongful death lawsuit has been filed by Christopher and Randi Decker in Thurston County Superior Court. It names Jacob Huff and his wife as defendants.
The younger boy had been riding on the tractor when he fell off and was run over by one of the tractor's wheels. The suit says the 7-year-old had been permitted to drive the tractor in the past but not with his younger brother on board.
Thurston County Sheriff's Sgt. Ray Brady said Friday no criminal charges were ever filed in connection with the incident.
The suit seeks unspecified damages.