Responses
Mainly - the phone network went down and the internet . Also in the three days while Nuowon was unconscious - no one came looking for survivors. There should have been helicopters, people searching the rubble (the normal things that happen after an earthquake). So you have to assume that whatever happened here also happened elsewhere. [They also had a pretty decent view from ten stories up to be all... oh crap]
it makes sense now thanks
but how did they know it was the end of the world tho.. please i'm dumb someone explain