Semi true story
Just watched a documentary called "the beckoning silence"
https://www.youtube.com/watch?v=N2M6rK3SpF4
The climbing scenes are very similar a 1936 summit attempt. Even the train part and dangling over the cliff....
Fascinating.
Almost as if the writer based the Eiger climbing part on the 1936 ill fated attempt.
Of course the rest is not real....