Pat,
I'm not saying that I can solve this problem for you, but perhaps somebody else reading this can if you can give us more detail about your great, great grandfather's death.
Like any detective work we need to answer the basic interrogatives such as who, what, when, where, and the like. Please provide the man's full name, his county of normal residence, the date of his death, the place of his death, and details concerning the circumstances of his death. The name of the vessel your ancestor was riding when he was killed would be an important clue, if you can provide it.
To answer your question directly, there is no one place to find more information about this man's death. It all depends on how well you can answer the above questions, because one or more of those answers gives researchers clues about where to look. If all you have is what has been passed along to you by mouth through your family, then share that and we will see. This is not always an exact science.
Bruce Nichols