10. The RMS Titanic Was a Royal Mail Ship
As such, the Titanic was officially responsible for delivering mail for the British postal service. It had a Sea Post Office on board, staffed with five mail clerks (three American and two English). They were responsible for the 3,243 sacks of mail on board the ship; those sacks contained 7,000,000 pieces of mail. None of that mail has been recovered.
As the mail storage room was located below the water line, it quickly began to flood. The clerks carried sacks of mail up to the sorting room. They planned to bring the mail all the way up to the top deck in the hopes of turning it over to a rescue ship.
Jago Smith, J. B. Williamson, Oscar S. Woody, John S. March and William S. Gwinn continued working right up until the end. They went down with the ship.