re: Is this the most depressing death scene in movie history?

No one will know what I'm talking about, but in 1963 there was a WWII movie called The Victors. One section deals with some GIs in France who find a little dog and adopt it, giving them some relief from the war.

Soon the outfit has to move out. One guy (Peter Fonda) who has become especially attached to the dog wants to take it with him, but realizes he can't. He gets in the squad's truck which drives away -- and the dog follows along.

Another soldier in the truck (Jim Mitchum -- curiously the two main roles in this scene were played by movie stars' sons) sees the dog tagging along. He takes out his rifle and shoots it.

The Victors is not a very good movie, but this scene has always stayed with me. I suppose it says something about something that I can watch dozens of soldiers in the film getting killed and not bat an eye, but when it happens to a dog I choke up.