On April 15, 1912, the ship R.M.S. Titanic hit an iceberg in the North Atlantic Ocean. The location of the Titanic was a mystery until National Geographic Explorer Bob Ballard found the wreckage of the iconic ship in 1985. The giant ship, said to be “unsinkable,” sank quickly–it disappeared beneath the waves less than three hours after hitting the iceberg. More than 1,500 people died in the disaster, with only 710 survivors.