London, July 8 (IANS) Actress Keira Knightley started crying while recalling the horror she witnessed on a recent charity trip to refugee camps in South Sudan. The "Pirates of the Caribbean" actress visited the victims of the region's civil war to coincide with the three-year anniversary of its independence from Sudan, which will be celebrated, Wednesday, reports contactmusic.com. "I'd never been to a refugee camp before, but I'd seen images.