His Majesty's Hospital Ship Britannic of White Star Line (known as HMHS Britannic or simply Britannic) was the final ocean liner by the White Star Line, which sank on November 21, 1916 due to a collision with a seamine. As of know it is the largest sea vessel ever sank.
Britannic was to be designed more safer and luxorious, drawing lessons from the RMS Titanic incident, which left 1,500 dead.
Britannic sank in only 55 or 57 minutes, half the time of the Titanic. Of the 1,065 people on board, 1,035 survived and 30 were dead. The perishers were reportedly pulled from the lifeboats and into the propellers, which were in the air and still moving.