The shock of losing loved ones suddenly is one of the most troubling of tragedies. But add to that the mystery of where their bodies might lie at the bottom of the ocean.

For the families of the explorers who died in the Titan sub implosion, those are feelings likely to haunt them forever, as they have for generations of other families who lost relatives under similar circumstances: the sinking of the Titanic itself over a century ago.

No bodies have ever been found from the wreckage of the Titanic at a depth of 12,500 feet, where over 1,100 passengers are likely to have dissolved after years of salt-water erosion and undersea life foraging the site.

A similar scenario is likely for the Titan submersible. And then, there are the harsh realities of the violent implosion itself.

“It’s not so much about deep sea as much as it is about the implosion. The force was compressing so rapidly that those bodies and souls had nowhere to go,” said Aileen Maria Marty, an expert in infectious disease and disaster medicine at Florida International University’s Herbert Wertheim College of Medicine.

Marty said that because of the way the sub imploded and likely crushed the bodies inside, “it’s very, very unlikely you’ll find any distinguishable body parts.”

The conditions of the deep sea are so unknown and challenging and the implosion so catastrophic that the families of the five people who died could be long left with questions about what exactly happened to them.