South Korea plane crash: Why was there a wall near the runway?

Notice to airmen
North Korea is launch of a satellite between April 12 and April 16; and as it is going up by rocket which will scatter debris, area Airlines need to be forewarned.

At least 19 airlines including Philippine Airlines, Japan Airlines, Korean Airlines and Garuda are rerouting to avoid the rocket or any falling debris. Alternative routes may add 13 to thirty minutes to flights. The Philippines has warned ships to steer from certain arieas where debris might fall into the Yellow sea. The second stage is expected to fall in water 140 km from Luzon.

However amateur sky watchers are saying in order for the satellite to get into the correct orbit, these experts say, they risk early stages dropping on allies’. The question remains North Korea Lying About Its Rocket Launch?