Frederick Fleet, who survived the Titanic sinking, called down and said, “Iceberg dead ahead.” How It Really Happened with Jesse L. Martin investigates the Titanic in a special two-hour episode Sunday at 9p ET/PT on CNN. | CNN Original Series

As the last lifeboat left the side of Titanic, there were tragically 1,500 souls remaining on the ship. How It Really Happened with Jesse L. Martin investigates the Titanic in a special two-hour episode - Sunday at 9p ET/PT on CNN. | CNN Original Series

Uncover the true story behind the devastating terror attack in this gripping and emotional CNN Original Series. | CNN Original Series