A submarine that takes tourists into the depths of the Atlantic to view the Titanic has vanished, sparking fears the five people thought to be aboard may have met a fate similar to those who sailed on the iconic ship. OceanGate Expeditions operates the submersible which drops tourists, who pony up $250,000 for a 10-day adventure, down for hours at a time from a vessel high above the Titanic, which rests some 2.5 miles down on the seabed about 370 miles off the coast of Newfoundland, Canada. On Monday, social media was on fire after news broke that the submarine...