With the exception of the Indianapolis, these aren't even close to being the worst. Still, it's an interesting list.
World's 10 worst shark attacks - Telegraph
"In 1985, Shirley Ann Durdin was diving for scallops in Australia's Peake Bay when she was attacked by a great white shark, said by witnesses to have been 20 feet long. The mighty fish tore the 33-year-old in half in its first strike as her husband and four children watched in horror from the shore. By the time rescuers arrived, all that remained was her headless torso floating in the water. Within moments, the shark returned and devoured that too."