KATHERINE HOURELD, MICHAEL GEORGY, SILVIA ALOISI ND BAZ RATNER THE screams of the dying gradually fell silent as the sky darkened. Around midnight, Berhane Gebrezigher, an ethnic Tigrayan, remembers lying in a ditch full of men who, like himself, had been shot and left for dead. He called out: "Is there anyone breathing?" When the sun rose, the old man faced a choice: die in the ditch or haul himself to the road. Painfully, he began shuffling upwards. It was mid-January, more than two months into an ethnic conflict that has convulsed western Tigray, an area of rich farmland in…