think it called ‘‘lost command’’ and its ww1 i think but tis a good film, just cant remember the name so i cant get me hands on it.
I believe it was The Lost Battalion
thanks Wolfgang Von Gottberg now perhaps i can find the film lol 
It is a good movie…based on actual events. The American commander (I can’t remmber his name) couldn’t deal with his survivors guilt and committed suicide some years later.