Please, for the love of math, stop this.
I'm not going to pull a no-true-Scotsman and say that there aren't people like you described that bill themselves as Libertarian, but at the same time most of us don't fit your mold, so please stop accusing us. It's as empty as if someone slandered socialists, claiming that they would starve to death without the government to hold their spoon. It's disingenuous and insulting, and does nothing to open up productive discourse, but does a lot to prevent it.
Libertarians are in favor of individualism and individual responsibility. Only the most shortsighted and foolish people are in favor of letting a stranger's life be destroyed because they made a hardheaded decision.
The Libertarian response to this is to wonder why they were letting their grandson recklessly burn garbage.
The Libertarian response to this is to expect people to be responsible enough to pay their fire department fees.
The Libertarian response to this is to expect the firefighters to prevent externalities by putting the fire out, and sending the fools who caused it the bill.
It is NOT the Libertarian response to this to herald it as a victory of the free market, or some such nonsense.
If someone in earnest represents Libertarian philosophy to you as "fuck you, I've got mine," that person probably has an ulterior motive, and is using the word Libertarian to mask their true intent. Some of us might take it pretty far, but at it's core, Libertarianism derives its logic from the Non-Aggression Principle. I think a quick reading would find that it takes a twisted interpretation to come to the conclusion that Libertarians encourage the destitution of people that make simple mistakes.
TL;DR: Please, can't we just be rational about these things, instead of just flatly slandering each other?