KYIV, Ukraine — As explosions boomed and smoke blanketed Ukraine’s capital early Friday, it was the same old fear for Nadiia Chakrygina. Like clockwork, she got her three children — Tymur, 13, Elina, 9, and 9-month-old Diana — out of bed and into a basement, where they waited, some asleep, some awake, for the strikes to be over. “Why do our children deserve this,” Chakrygina, 34, told NBC News in a telephone interview. “Why are they living under strikes? Why can’t they get proper sleep and go