I finally ended up watching this show that I had previously recorded and here is my summary:
James Cameron has gathered many experts on the Titanic to review what happened to the ship after it hit the iceberg, how it sunk and how it ended up the way it is at the bottom of the ocean.
Using actual footage of the wreck and computer models they derive how the flooding started in the forward compartments, how it propagated along the ship, how it was listing upright and the eventual break up in two separate sections.
The experts analyzed all the debris on the ocean floor and explained how each piece detached from the ship, the way it moved in the water and its eventual resting place.
Cameron also points out some errors from his 1997 film (the break happens further forward) but he also discusses why he did not make any alternations in the recent re-release.
Finally it ends with a detailed computer animation of the sinking using the most up to date data gathered in this investigation.
Well done and recommended to those who like this type of investigative show.
Clips are also available from this National Geographic web site link