Grainger County Sheriff Scott Layel said 11-year-old Nathan Lynam died Thursday night at Children's Hospital in Knoxville. Ten-year-old Noah Winstead of Morristown died at the scene Wednesday afternoon.
Tennessee Wildlife Resources Agency spokesman Matt Cameron said a marine surveyor was helping Thursday as investigators looked for the source of the electrical charge. The boys were shocked as they swam near two houseboats in Cherokee Lake.
Layel said it wasn't immediately clear whether the boys encountered an electrical field in the water or if they were shocked when they touched a metal ladder to one of the houseboats.