DATELINE Preview: March 11-13

Coming up on Dateline: 

FRIDAY, MARCH 11

When a newlywed couple go diving on the Great Barrier Reef for their honeymoon, no one would have believed that just one of them would return to the surface alive. Dennis Murphy reports on how investigators attempt to fill in the pieces of this mysterious death and try uncover whether it was an accident or something worse.

SUNDAY, MARCH 13

Caught on tape! "Dateline NBC" takes an look at the wild and unpredictable world of animals-- from heartwarming stories of animal rescues to terrifying animal attacks.