This short story is about an engineer who sabotages the engines on a floating city where the rich and well-to-do live apart from normal humanity causing it to crash on Earth killing everyone on board...
That would be Shah Guido G. (1951), I believe.
It is, indeed by Asimov, and is one of the stories where the entire plot is nothing but the setup for an atrocious pun. (Specifically, it's what's referred to as a 'Shaggy Dog' story. Don't believe me? Look at the title again.. Shah - Gui - doG.)
Short synopsis: The floating city has been hovering on the edge of it's maximum load limit for a while. The 'hero' of the story arranges for all of the Guardians (the 'Waves'), in their ships, to land at once, overloading the generators that kept the city afloat, and causing it to come crashing to the ground.
This is all for the pun that, once again, Atlantis (for so the floating city was named)
sank beneath the waves.