Re: This nearly happened in 2012
The problem is that we can fix pretty well anything in our technology, using other bits of our technology.
A Carrington event would take out pretty much everything, leaving sod all to do the fixing.
How do you fix stuff when you don't have the transport to bring the parts from the factory that can't make them? And what transport you do have is desperately trying to distribute food.
Some bits take a long time - I seem to recall that the big transformers needed to get the grid running take many months to make, and they can't make more than a very few at a time.