Kyiv cancels some Children’s Day events as Ukraine loses another young life.

“War. I slept well, woke up and smiled.”

President Volodymyr Zelensky of Ukraine read those opening words from “The Diary of a Young Girl” by Anne Frank at a conference focusing on children on Wednesday afternoon as he sought to highlight the toll that Russia’s invasion of his country has taken on its youngest citizens: In 15 months of war, he said, at least 483 children had been killed, and other estimates suggest that the toll is even higher.

“When there are air-raid sirens every…