It is one of the most shameful stories of the post-Cold War world. One million Tutsis were slaughtered by the Hutu majority in Rwanda while the West turned a blind eye. As the U.N.s Genocide Convention created to make sure genocide would never happen again marks its fiftieth anniversary, FRONTLINE examines the role of the U.S. and the U.N. as they ignored the warnings and evidence of impending massacre in Rwanda.