Heavy monsoon rains and flash floods have killed at least 51 people in Bangladesh and affected more than 1M residents, officials say.Army and Navy units are delivering food, water and medicine by boat to isolated communities as power outages, damaged roads and broken communications hamper relief, and Disaster Management and Relief Minister Iqbal Hossain urges evacuations to government shelters.Landslides in Cox's Bazar Rohingya refugee camps have killed 16 refugees and swept through a school that killed several students and a teacher; experts link the worsening floods to climate change and officials warn of further flooding in northern regions.