Sluszny visited an underground cave with a friend in Salses-le-Chateau, in southern France, on Thursday. When the two were at a depth of 125 metres, things went wrong. Sluszny lost contact with his fellow diver when the cable between the two men snapped.
His companion managed to return, but Sluszny went missing. A long search proved fruitless. Antwerp resident Sluszny is 56 and built a reputation for extreme challenges.
The feats he achieved include swimming between white sharks without protection, walking down a vertical wall and jumping out of a hot air balloon at 6,720 metres altitude to do the highest bungee jump ever. About the sharks, he said: "It's not dangerous. Actually, they don't like to eat us. When it happens, it's a case of mistaken identity."