Murphy's Law #3(Paraphrased): With any expensive & complex machine, it will be the 25 cent part that fails and brings everything to a screeching halt!!!

With society being as complicated as it is, it really doesn't/wouldn't take much to start that 72 hour clock to commenced the countdown to the stone age (for the 4th or 5th time around).

That was at the top of my list as well.