IMPORTANT:
This is not related to the Walking Dead but its something I learned while interning at the Department of Water and Power back in High School:
In the event of any long term disaster, infrastructure is fukked because it is purposely designed to be self-obsoleting, with a monthly kill-switch.
I will try and translate that.
So, each month you pay your phone bill and you have service for a further month, right? The system is set up so that upon receiving payment someone (or an automated system) gives you another month of service.
But, in the event of a mass disaster, after a month we will all lose phone service. Not because there is a problem with the towers or satellites. Simply because the system is designed to self terminate and check for exemptions (people that paid) instead of the other way around. It should be designed to continually renew and check to see who did NOT pay, and halt their service. Meaning in the case of disaster, if the person/system is not up, service continues for everyone.
This is the case of water, power, phone service... almost everything is set to auto-shutoff instead of remaining on because this way in case of human error or system error the companies make money instead of losing it.
The result though, is that in the case of worldwide disaster, we have a ticking clock of a billing cycle before everything goes dark despite the technology, pipelines and everything else being correctly in place.
Greed.