Now I am become death, the destroyer of worlds (idea)

In the the GURPS Technomancer RPG world by David Pulver, this phrase completed a necromantic ritual begun centuries before that in combination with the detonation of the bomb brought magic back to the Earth.

From then on out, any atomic or nuclear explosions form a manastorm, kind of like a standing magical tornado. there have been two detonations in Technomancer; the original Trinity blast and an Antarctic blast by Russia. A third would cause the entire world to be engulfed by a manastorm, so don't go nuking people. Not that you need to when you can lob big-ass fireballs.