1 Head Death: Interesting interpretation. That non-magical explosions count as "fireballs".
2 Death of Insanely Overpowered Fireballs: "Magical" isn't in my job description, sir.
3 Head Death: Are you fishing for a promotion?
4 Death of Insanely Overpowered Fireballs: Actually, I'd just be happy to keep this one for more than a few days.

Fireball is the name of a well-known spell in Dungeons & Dragons (and probably several other fantasy roleplaying games, based on its original use in D&D). Mostly, when I use the word "fireball" I'm thinking of a magical effect. But "fireball" does have several non-magical meanings. In particular, it's often used as a synonym for a bolide, an exceptionally bright meteor.

I suppose someone could get killed by a bolide. That would be pretty spectacular and insanely overpowered.

For completion, there are lots of other things called fireball as well. I'm now trying to imagine death by an insanely overpowered Fireball Cinnamon Whisky...