Why haven't the remains of Titanic passengers been found?

More than 112 years after its sinking, the Titanic still hides its secrets, including the failure to find the remains of its victims.

The Titanic sank on April 15, 1912, in the North Atlantic Ocean, four days into its maiden voyage from Southampton to New York City.

The British passenger ship had about 2,400 passengers on board when it struck the iceberg shortly before midnight. The devastating event saw more than 1,500 people killed in one of the deadliest commercial shipping disasters in modern history.

The wreckage of the Titanic was found on September 1, 1985, at the bottom of the Atlantic Ocean, about 4,000 metres underwater.

While experts, using the most advanced underwater photography equipment, found a large number of passengers' belongings in the wreckage, they never found any skeletons or human remains.

“I didn’t see any human remains,” James Cameron, director of the 1997 blockbuster “Titanic,” told The New York Times in 2012. “We saw clothing. We saw pairs of shoes, which strongly suggests that there was a body there at some point. But we never saw any human remains.”

Given that Cameron has visited and explored the wreck some 33 times (and claims to have spent more time on board than the ship's captain), if he didn't see any human remains, we can assume that there really aren't any human remains there.

The question of why no human remains have been found in the shipwreck has puzzled Reddit users over the past few days, but fortunately, there are some simple answers to explain it.

Life jackets

Although there were not enough lifeboats on board, many of the passengers and crew were able to wear life jackets, meaning they remained afloat even after succumbing to the freezing cold waters of the Atlantic.

Thus, when a storm followed the shipwreck, they were likely swept away from the wreck site and carried away by ocean currents over the following weeks and years.

Depth of debris

Bones have been found in shipwrecks much older than the Titanic, however, none of the skeletons on board the latter have survived.

While this is partly due to the work of deep-sea "cleaners," such as fish and other organisms, as IFL Sciencenotes points out, it is also likely a result of the depth at which the ship lies.

“The problem you have to deal with is that at depths below about 914 metres (3,000 feet), you’re below what’s called the calcium carbonate compensation depth,” deep-sea explorer Robert Ballard explained in 2009. “The water in the deep sea is saturated with calcium carbonate, which is, as you know, mostly what bones are made of. For example, in the Titanic and the Bismarck, those ships are below the calcium carbonate compensation depth, so once the creatures eat their flesh and the bones are exposed, the bones dissolve.”

The "calcium carbonate compensation depth" is defined as the depth of the sea or ocean at which the rate of dissolution of calcium carbonate increases to the point that no carbonate sediments or organisms can accumulate or be preserved on the seafloor.

Some believe that there may still be some bodies preserved in sealed parts of the ship, such as the engine room. 

However, more than a century after the tragedy, the idea that remains could be found seems unlikely.

Searches for remains will likely be fruitless.