MINAB, Iran — The sun set over this southern Iranian city, and Heydar Sadeghi was where he can be found almost every evening: on a bench next to the shattered remains of his grandson’s school. His face was soaked with tears.

A banner strung around the rubble showed the faces of children and teachers killed here by an American airstrike on Feb. 28, the first day of the war on Iran . Among them are Sadeghi’s 11-year-old grandson Hami and the boy’s mother, Neda Salehizadeh.