McDaniel was last seen cave diving at Vortex Springs in Ponce de Leon, Florida on August 18, 2010. He entered the cave alone at 7:30 p.m. The cave is 1,600 feet in length and drops as much as 165 feet deep. McDaniel has never been heard from again. An extensive search turned up no indication of his whereabouts; the searchers only found McDaniel's decompression tanks at the mouth of the cave, unused. He left his truck in the Vortex Springs parking lot. McDaniel is presumed to have drowned.