Entertainment Music Country Official on Craig Morgan's Son's Death: 'We're Not Sure Why He Didn't Resurface' Jerry Greer, who died in a tubing accident, was still wearing his life jacket when his body was recovered By Danielle Anderson Published on July 12, 2016 04:15 PM Share Tweet Pin Email Photo: Courtesy Monarch Publicity The body of Craig Morgan‘s son, Jerry Greer, has been found, but what caused the 19-year-old’s death while tubing on Kentucky Lake in Tennessee is still a mystery. Greer was wearing a life jacket when he came off the tube and entered the water on Sunday, and was still wearing it when his body was recovered from the lake on Monday evening. Authorities do not yet know why despite the presence of the life jacket, Greer did not come up from under the water. “This was just a tragic accident as far as hitting a wave and coming off [the tube] and not coming up,” says Sheriff Chris Davis, who led the recovery efforts. “We are not sure yet why he did not resurface, although the jacket he was wearing was not Coast Guard approved,” a rep for the Tennessee Wildlife Resources Agency, who is handling the investigation, tells PEOPLE. “He was legal because of what he was doing and the operator had proper life jackets on board, but the jacket itself was one that many skiers and wave board users wear. As an agency, we prefer jackets that have the Coast Guard approval.” Don’t miss a beat of country music news, photos and videos. Click here to get all this and more in the PEOPLE Country Newsletter. Greer was a 2016 graduate of Dickson County High School and planned to play football for Marshall University in the fall. “Jerry always performed in every event full speed with a gigantic amount of energy. You could count on him to give all he had every practice, game or play,” Greer’s former coach Troy Williams told The Tennessean. “He was high energy and everyone was always more upbeat when he was around. He was very competitive at every turn.” “If he was there, he was there to win,” Williams added. “These attributes are great when you have to go into battle on the football field and great attributes to succeed in life. A life cut too short and we as a football brotherhood will miss him.” Condolences from friends and colleagues of Morgan continued to roll in Tuesday as the community mourned. Funeral arrangements are pending.