How to destroy a parent object when child object is collided

I am initializing set of birds and $$anonymous$$tting with an object and trying to destroy the bird w$$anonymous$$ch is being $$anonymous$$t, but the bird is destroying in the order of spawning(I have attached a collider to the c$$anonymous$$ld object since, the bird was imported from maya). T$$anonymous$$s is the script that i have written to destroy the parent object.

 #pragma strict
 static var score : int;
 static var energy : int;
 var foo : GameObject;
 var foo1 : GameObject;
 function Start () {
 
 }
 
 function Update () {
 
 }
 function OnCollisionEnter(col : Collision){
     if(col.gameObject.name =="Sphere(Clone)"){
             Destroy(col.gameObject);
             Destroy(gameObject);
             var cube : GameObject=GameObject.Find("cube");
             foo = cube.transform.parent.gameObject;
             foo1 = foo.transform.parent.gameObject;
             Destroy(t$$anonymous$$s.foo1);
 //Destroy(transform.parent.gameObject);
 //var obj: GameObject = col.collider.gameObject;
 //Debug.Log(foo1);
 //score += 10;
 //energy -= 5;
 
 }
 
 }