Why rescuing a deep sea sub in the depths of the ocean is nearly Impossible!

As rescuers in a remote area of the Atlantic Ocean are racing against time to find the missing submersible carrying five people on a mission to document the wreckage of the Titanic, we look back to the endeavour launched by filmmaker James Cameron to explore the depths of the ocean. In this 2012 60 Minutes story, Cameron talked about what made him want to explore the blackest depths of our oceans, as far as man has ever ventured, piloting a tiny sub eleven kilometres below the water's surface.