Back to the Titanic documents the first manned dives to Titanic in nearly 15 years. New footage reveals fresh decay and sheds light on the ship's future.

For the 20th anniversary of "Titanic," James Cameron reopens the file on the disaster.

James Cameron brings together some the world's leading Titanic experts, including engineers, naval architects, artists and historians, to solve the lingering mysteries of why and how the 'unsinkable' ship sank.