Korean refugees flee south, away from battle zone, during Korean War

The Korean War erupted unexpectedly as North Korean forces crossed the 38th parallel into South Korea, causing a massive civilian exodus. In response, President Truman committed US forces to support the UN's ceasefire efforts, joining the conflict five days later.

What event triggered the violent civil war mentioned in the text?

Which troops crossed the 38th parallel into the Republic of Korea?

What was the situation of the civilian refugees during the invasion?

What action did President Harry S. Truman take regarding the UN ceasefire order?

How many days after the initial conflict did the US commit to action?