"Leviathan Five" (1964).

In Kraft Suspense Theatre's "Leviathan Five" (1964), scientists face a desperate choice when they are unable to escape from their underground facility. Featuring Andrew Duggan, Arthur Kennedy, Frank Maxwell, Frank Overton, Harold Stone, and Robert Webber, the episode was scripted by Berne Giler, David Giler, and The Big Heat's William McGivern.