John Bova, left, of Lower Shaft, son of lost Sheppton miner Louis Bova, unveils a state historical marker Saturday near where his father is entombed at Oneida Slope #2. Helping is J. Ronnie Sando, 77, of Hazleton, believed to be the lone surviving Sheppton rescuer and former employee of Pagnotti Enterprises. The Sheppton Mine Disaster, in which three miners were trapped 320 feet underground for 14 days, captured the world's attention in 1963. Saturday's moving event took place on the 52nd anniversary of the rescue of miners Henry Throne and David Fellin. Despite heroic attempts, Louis Bova was never found.