Undefined Behavior Killed My Cat Undefined Behavior Killed My Cat

It's well known that undefined behavior can kill your cat [citation needed].
But can it?

Your Task


Write a program that invokes undefined behavior.
Describe a scenario that starts with the above program being run, resulting in a Felis catus ending its life while in your ownership, as a result of the aforementioned UB.
Estimate the probability for each stage in the scenario.
Calculate the total probability that a single run of the program would kill your cat.


Rules


This is a popularity-contest, so be creative if you can.
This is a programming related challenge, so the chain of events should be mostly within the computer, not in the real world (of course, if has to reach the real world if that's where your cat is).
If you choose a language that doesn't have undefined behavior, use something similar.
No animals may be harmed in the production of your answer.


Scoring

Vote count plus the scenario's total probability (which can't exceed 1).

Example in C:

main(){printf();}


Scenario:


printf called with garbage from the stack - undefined behavior. Probablity: 100%.
The first parameter happens to be the string Your cat is ugly!. Probablity: (1/256)17 = (1.148 * 10-37)%.
Seeing the message, you pick up your gun and shoot your cat. Probability: 3%.
The cat dies. Probability: 93%.


Total probability: (3.202 * 10-39)%.
C

Most answers to this question misinterpreted the question in that it was killing the cat process on a UNIX system. Here is a program which can cause the demise of a biological lifeform of the species Felis Cattus as specificed by the question.

This example runs on Windows, but it could be easily ported to most UNIX operating systems by replacing iexplore -k with the command to launch an installed web browser.

#include &lt;stdlib.h&gt;
#include &lt;stdio.h&gt;    

int main() {
    char i; // uninitialised
    printf("Redirecting you to a website which will inform you how to properly feed your cat.");
    if (i != 42) {
         system("iexplore -k https://pets.stackexchange.com/questions/tagged/cats+diet");
    } else {
         system("iexplore -k https://cooking.stackexchange.com/questions/tagged/chocolate");
    }
    return 0;
}


This program pretends to provide advise about cat diet to the user. 

It will start Internet Explorer and direct the user to pets stackexchange listing lots of helpful questions about how to feed cats. There is, however, a low (1/256) chance that it will send the user to cooking stackexchange instead listing tips how to prepare dishes containing chocolate, which is highly toxic to cats. To make matters worse, it will launch internet explorer in kiosk mode (fullscreen), which hides the address bar and is hard to escape from for a non-tech-savy user.

This clever ruse will coax the user into feeding their cat chocolate believing that it is an appropriate diet for it, thus causing them to inadvertedly kill it.