NASHVILLE — An autopsy confirmed that a country music star's son whose body was found in a Tennessee river in July drowned.

Jerry Greer's death was accidental, the autopsy report released Monday said. Greer, 19, was the son of entertainer Craig Morgan and his wife Karen. Greer's body was found in Kentucky Lake in Humphreys County, Tenn., on July 11. He had been missing overnight.

A toxicology report shows that at the time of his death, Greer tested positive for marijuana and a low level of alcohol in his system.

Erin Carney, assistant medical examiner for Humphreys County wrote that Greer disappeared in the water about 4 p.m. July 10 while tubing with friends.

According to a case summary, Greer was riding on an inner tube behind a boat when the inner tube flipped and Greer went under the water. He did not surface and his body was discovered the following day about 9 p.m.

When rescue crews pulled Greer's body from the water he was still wearing a life jacket, authorities said.

Greer, who just graduated from Dickson County High School in May, planned to attend Marshall University in Huntington, W.Va., in the fall.

Greer was close with his dad, an Army veteran who has had several hits, includingTough, Almost Home, That’s What I Love About Sunday and International Harvester.

Morgan is the host of Craig Morgan All Access Outdoors on the Outdoor Channel. The show takes Morgan on adventures around the world, and Greer sometimes went with him. The program’s website shows Morgan and Greer posing with a goat they shot in Hawaii.

Greer was one of Morgan’s four children.