Wildlife officers are investigating the accident and haven't determined how the men were thrown from the boat, McCullough said.
SC deputy dies in boating accident while training on lake →
Department of Natural Resources Capt. Robert McCullough says three people from the Anderson County Sheriff's Office and the U.S. Army Corps of Engineers were on Lake Hartwell when they were all knocked out of the boat Thursday morning.
The Latest: Deputy killed in boating accident volunteered →