Would you grab a bunch of weapons and kill people?
Would you rape?
What would you do?
If the end of the world involved the power going out, there's two ways this could go:
1) I am awake and just think the power went out. Once sounds would come from outside (or inside if I'm working) I'd watch how others are responding and go from there basing it on the nature of what's happening specifically there.
2) I am asleep, and the power going out has knocked off my alarm. I would end up sleeping past the set time I had, wake up, and see I am late to the whole end of the world gig. I'd miss out on first claim of pretty much everything and be screwed for supplies. I am not one of those end of the world backyard bunker types, so I would have to find a means of bumming off another's success.
If the end of the world still had power, internet, and all that, I'd just check online for details and see if the cable still worked for trying to catch the news. Even unaware of danger, the television and internet would be buzzing about the issue, even on my regular non-news related channels.
^ What luna said.
Rape and murder would be the last thing on my mind unless killing is conducive to achieving my first goal. Survival.
Any type of sex, especially rape, would also be highly likely to kill me in a post-apocalyptic landscape. Rape is out of the question, end of the world or not.
I'd work with my best friend to build an aftermath-infrastructure to live in. I'm great at getting support and followers, while he's good at getting resources and solutions.
What did Lord Varus say about Littlefinger? "he would burn the entire realm down if it meant he could be king of the ashes."
So the world ends itself: We still get to be Kings of the ashes.