Ace in the Hole (Billy Wilder, 1951)

Charles Tatum, a down-on-his-luck reporter, takes a job with a small New Mexico newspaper. The job is pretty boring until he finds a man trapped in an old Indian dwelling. He jumps at the chance to make a name for himself by taking over and prolonging the rescue effort, and feeding stories to major newspapers. He creates a national media sensation and milks it for all it is worth - until things go terribly wrong.