When it sank, hundreds of people died on board and in the freezing water, did the bodies sink with the titanic and are they still on board the wreckage or have they decomposed?
Possibly but we don't know for sure.
Not all the bodies sank though. Some were recovered and taken to Halifax, Nova Scotia, where they were buried in Fairview Lawn Cemetery. They included among their number one J. Dawson. His grave received lots of flowers after the release of the 1997 film, although the initial and surname are just coincidences.