I just finished watching "Judgment at Nuremberg" and realized that the first 25 credited actors are all dead with the exception of William Shatner. That came out in 1961 and got me thinking of which most recent movie have all the cast members died.
Judgement at Nuremberg is a good example as it is a film with a huge cast. From two years later, It's a Mad Mad Mad Mad World has an even larger cast, most or all of whom are no longer with us. Interestingly, it's another Stanley Kramer movie.
I know 1961 was a long time ago, but it doesn't seem like 24 of the 25 cast members should be dead. Let's just say someone was born in 1938, that would make them 82 now and 23 when the film came out. I feel there should be more of the cast alive.
An Unremarkable Life (1989) has three main roles - Patricia Neal, Shelley Winters and Mako, all now dead. But of course there are actors in smaller roles who are still alive. This is a tough question -- I guess it would be almost impossible to pinpoint a film which provides the perfect answer, as most films from at least the late 50s/early 60s would, I would imagine, have at least a couple of actors still living.
Well considering Shatner was considerably younger than most of the cast... Maximilian Schell was the only other principal, I believe, born as late as 1930, and he lived to be 83. If Tracy, Widmark, Dietrich etc were still alive they'd be well over 100 - even Clift would be 99, Garland 97. I think it'd be more unusual for multiple members of a cast from an almost 60 year old film to still be alive, considering most of them were in their forties and above at the time!
There probably should have been... Garland was clearly too old for her character. But Tracy, Widmark, Lancaster etc were playing older, more experienced veteran characters.
I think Schell seemed like a man in his early thirties, which he was at the time. Anyway, he walks off with the movie IMO.