Destructors are called in reverse order of constructors. First destructor of most derived class is called followed by its parent’s destructor and so on till the topmost class in the hierarchy.
You don’t have control over when the first destructor will be called, since it is determined by the garbage collector. Sometime after the object goes out of scope GC calls the destructor, then its parent’s destructor and so on.
When a program terminates definitely all object’s destructors are called.