The sinking of the RMS Titanic is perhaps the most famous shipwreck in history, but its sister ship, the lesser-known HMHS Britannic, also suffered a tragic fate. During World War I, the luxury cruise liner was requisitioned as a hospital ship, the largest in the world at the time. As it was sailing through the Aegean Sea on November 21, 1916, it struck a mine and went down off the island of Kea in less than an hour. Thirty of the more than 1,000 people onboard perished when their lifeboats were hit by the ship's whirling propellers. The Associated Press...