CNN  —  Content warning: This story contains descriptions of violence against children and images viewers may find disturbing. Bhone Tayza had been impatient to start school. A broken arm had kept the 7-year-old home while the other kids began their lessons, but now that his cast was off, he couldn’t wait to join in. His mother, Thida Win, was still worried. “Just stay home for today,” she recalls telling her son on his third day back at school last September – but he went anyway. Hours later, the airstrike hit. Thida Win was home, in the central Sagaing region of Myanmar, when army helicopters began firing “heavy weapons” including machine…