Aerial bombardment and landmines, Korea, 1950

In Korea, the United Nations took its first enforcement action against an aggressor. On June 28, the US Air Force began operations against North Korean invaders, supporting Republic of Korea forces and targeting military sites north of the 38th parallel. Despite efforts to delay the North Korean advance, Republic of Korea forces were pushed back, and by July 2, the town of Siouan was under North Korean control.

How did the North Korean forces manage to advance during the conflict?

What was the significance of the town of Siouan in the context of the conflict?