Authorities have completed their investigation into what caused the death of a 16-year-old from Graettinger.

Noah Flaherty was found unresponsive in the 600 block of North Walnut Street in Graettinger June 24. He was later pronounced dead at the hospital.

The investigation by the Palo Alto County Sheriff’s Office found Flaherty was attending an underage alcohol party that night.

Police say an 18-year-old female and juvenile male at the party located Flaherty sitting on the back truck of her vehicle, and told him to get off the vehicle.

Authorities say Flaherty then shifted his body and was stretched over the vehicle’s roof. He then rode on the vehicle into town without the driver or passenger knowing.

Police say Flaherty then attempted to exit from or fell off the back of the vehicle , striking his head on the roadway, causing a severe head injury..which authorities say was the official cause of his death.

An 18-year-old, Payton Brower, of Terril, Iowa, has been charged with possession of alcohol under the legal age and supplying to minors, both simple misdemeanors. No other charges have been filed.