I believe that one of the best depictions of what occurred here is through the movie Hotel Rwanda. Take a look at the trailer below.
The Hutus and the Tutsis were two ethnic groups that occupied Rwanda. Both speak the same language, live in the same area, and follow similar customs. Yet, Tutsis claimed to be taller and thinner with some even attributing their origins to Ethiopia. Furthemore, when the Belgian colonists arrived in Rwanda in 1916, they furthered the differentiation. They handed out different identification cards and believed that Tutsis were superior to Hutus. This led to years of suppressed frustration and anger and eventually an ethnic war that climaxed in 1994. There were 800,000 people killed over the course of a 100 days. This event has become a major black-eye to the world. It has shown that the UN, the world's largest peacekeeping force is completely ineffective, and that rest of the world was largely apathetic to such occurrences.
As I just reflect upon the genocides and human rights abuses that occurring all over the world today, it frustrates me that there is so much apathy. I personally confess that I was not very moved when I heard about the horrors occurring under Gadhafi's regime at first until I really sat down today to research what was going on. There is just something sad when a dogfighting ring owned by Michael Vick ignites the entire nation in outrage, yet the massacres of people all around the world become largely ignored.
Check out this article read up a little more on what happened.