Debris and rubble litter the streets a week after a tsunami-sized flash flood devastated the Libyan coastal city of Derna, sweeping thousands to their deaths, the city. Traumatised residents, 30,000 of whom are now homeless in Derna alone, badly need clean water, food, shelter and basic supplies amid a growing risk of cholera, diarrhoea, dehydration and malnutrition, UN agencies warn. IMAGES