My great great grandfather died in the River Seine in ouan. Could someone help me find were he was?

... buried or if he he was ever buried?
He was on the SS Alto in Ruan, France on the river Seine. He was a fireman on the ship putting coal into the furnaces. The Ship sank on the 16th of July 1916, BUT he fell overboard on the 5th of April at Ruan Harbour in France on the River Seine.
Any information on what happened to him (his name was Micheal Black) would be greatly appreciated!