I went to Rwanda in 1993 just before the killing started. There were displacement camps everywhere, the tension was papable. It is said that Rwanda never suffered the ravages of the slave trade and consequently had a well established but dense popualtion on its highly fertile soil but more significantly it had a society that had a highly defined awareness of ethnicity. An individual’s ethnicity was clearly stated in their ID cards, introduced by the Belgian colonists and never removed by an independent government. Perhaps the ethnic divisions were useful for control.
When the Hutu killing spree started it was easy to pick off people. Around 800,000 people mostly Tutsi were slaughtered. Around half of that figure in the first week.