The Mystery of Britannic (2017)

Titanic’s sister ship, the HMHS Britannic, sank off the coast of Greece in 1916, four years after the Titanic went down. It had been converted into a hospital ship and troop transport, and like its sister ship, broke into two pieces as it sank. Unlike Titanic, however, only thirty people lost their lives out of the thousand-plus who were on board.

The wreck now lies about four hundred feet below the surface of the Aegean Sea, and a question about the sinking still remains: Why, despite improvements in safety, did Britannic sink faster than Titanic?