NYALA, Sudan, May 2 — Hawa Muhammad, 15, lost just about everything when the men on horseback came. They took her family's horses, donkeys and small herd of goats and sheep. They took her cooking pots and her clothing. They took her mother and her father, too. "The men on horses killed my parents," she said, referring to the Janjaweed, loose bands of Arab fighters. "Then the planes came." Now it is she to whom her six younger sisters turn when their bellies rumble. She recounted her tale as if in a trance. Hawa left her village on the run...