This would be a very ugly scenario, but it is how nature has addressed an imbalance in the past. Some thing like the plague hitting this country would be a catastrophe because we are completely unprepared and we've grown soft. When things start turning off, like electricity, people are going to freak out. That'll be when we'll have to start thinking of way to survive until things settle down and basic services are restored. I'll be collecting up everyone improtant to me and heading for the hills.
Lack of power, Lack or water, lack of gas, Any one of these things will cause people to panic and go nuts. If you take away more than one thing and chaos is rampant.
A good bird flu can do more than just or two and that will send many back to the dark ages because they do not know how to function without any one of these things let alone all of them. I have shown my kids how to build a fire and collect food if need be. The water and other survival stuff will be taught if they wish as I let them make their own decisions there.
KN,
Yup, I understand what you are saying. I forget which plague it was, but one came through that they say killed one in three people. That is a tremendous mortality rate. Basic services would end if that happened. It'd be time for people who know how to survive to do so.