Yep, my first thought as well.
"52,000 US military casualties"?? Horse manure.
First, NK has a massive number of people in its military, and a lot of military hardware (practically its entire GNP has been used to build up its military instead of feed its people).
Second, keep in mind that NK has an unknown number of "nuclear devices" now, and missiles. One nuke lobbed over (or driven using a nondescript truck into) the highest concentration of US troops in the region would produce a very large number of casualties.