Louis Zamperini, the World War II prisoner of war and former Olympic distance runner, has passed away at the age of 97. Zamperini was the subject of Lauren Hillenbrand's best-selling book Unbroken. His family says he battled for 40 days against pneumonia before succumbing. "Leaving behind a legacy that has touched so many lives, his indomitable courage and fighting spirit were never more apparent than in these last days,” the family said. Zamperini was the youngest-ever American Olympic qualifier for the 1936 Olympics in Berlin, where he placed eighth in the 5,000 meters. His final lap of 56 seconds, however, got him a one-on-one meeting with Adolf Hitler. Zamperini then enlisted in the Army Air Corps in 1941. After his plane crashed, he spent 74 days on a raft before being captured by the Japanese navy. Zamperini was imprisoned for two-and-a-half-years as an unofficial POW (and even declared killed in action by the U.S.). A movie adaptation of the book, directed by Angelina Jolie, will hit theaters on Christmas Day.