The Earth is being disassembled by aliens, and even Superman can't stop them. The aliens' ships mark ground with long red lines before cutting, and the pieces are taken away, no one knows where. No one knows what happens to the people living there, either. There is a striking illustration of the Earth opened up like a diagram in a geology textbook with the core and mantle showing, as Superman flies in space wondering what's happening and what he can do about it. (Incidentally, I would love to see a copy of this illustration again.)
I'm not sure what happens next, but evidently he allows himself to be taken along with a slice of planet in order to find out where it's all going. To his surprise and relief, he finds the missing people lolling in a resort. They're taking great care of us, he is told. The aliens, who have been careful to say nothing up till now (for reasons that make no sense whatsoever other than to increase dramatic tension), now explain that one of their spacecraft leaked some extremely dangerous fuel onto Earth while passing by, and in order to decontaminate the planet they have to take it apart and process it. Earth is put back together and not a teacup is out of place.
I read this in a comic book published in English, presumably "Superman" comics, in the 1960s.