Imagine (and it is just that) or redefine the term "darkness", rather than simply physical camp fire survival, could mean, for example, everyone goes blind and deaf for 3 days! In that case, many would not know to hold on because not only will there be a cease in electricity, there will be no direct language communication. That would be a global pure spiritual cleansing which you just curl up with others by feel and sleep for 3 days.