EARTH: Superman and Lex killed in battle

A world visited by Lois Lane from Earth 1 of the DC Pre-Crisis cluster. On this world, Luthor killed Superman with a kryptonite bomb, but was fatally injured himself. While the citizens of Kandor selected one of their citizens to become the new Superman, a Superman robot was activated to keep the world from finding out the truth.

Here, Atlantis never sank below the waves and was a nation known to the world.