I watched a discussion from a former pilot who made it sound like the concrete structure that the plane ran into at the end of the runway was highly unusual and unnecessarily strong. Usually those locating beacons are mounted on very light plastic poles or on a tube frame. The heavy concrete foundation seems to be a significant factor in turning this from a rough emergency landing into a major disastor. I would imagine South Korea will revisit code for what kinds of structures can be built on the ends of runways after this.