Nights in Rodanthe
(2008)

Paul (Richard Gere) goes to South America to reunited with his estranged son (James Franco) after falling in love with Adrienne (Diane Lane).  While he is gone the two exchange love letters.  On the night he is supposed to return she waits for him, but he never appears.  The next day his son appears at the door with a box of his father's belongings and tells her Paul was killed in a mud slide before he left.  He thanks her for changing his father for the better.

Thanks Mary C!