reporter: south koreans are numb to the onslaught of threats but they re also practiced in living it. monthly civil defense drills where people in seoul practice city wide emergency evacuations. seoul is a city of 11 million people one hour from the dmz. what all of these people know is if there s some sort of attack, they know to head underground. shelter or the subways, which double as underground bunkers. seoul is a maze of underground concrete halls, but most of the residents don t believe they ll ever have to use them. why south african native wayne n nschutte isn t worried. hoping the talk as loud as it gets stays just that, talk. the south korean presidential office is dismissing this latest threat against foreigners saying that this is just more psychological warfare from the