I went even further than that. I checked all the programs on at that time. They were music and a comedy show, and quiz shows, and news. There was nothing else!
11 seconds sound clip from the The Adventures of Superman - The Mystery of The Walking Dead classic radio series.
You can hear this line at 00:19:50 in the radio play.
Quote context
[...]
- I don't know, but we've established one thing, at any rate: he's not alive, he's dead.
- Was he alive when I heard him on the radio?
- You couldn't have heard him.
- I did!
- He was in his cell. Now, that was definitely your imagination.
- What you heard was the end of a mystery program.
- Was it?
- And you still think he's alive?
- Don't ask me what I think! I'm telling you what I know, what I heard, what you heard!
- Okay, then there's only one thing to do.
- What?
- Krishna's body is lying in state at the Temple of Truth. You and I are going over there to see it!
- Clark, I... I'm afraid to go in there. All the attendants know me.
[...]