Something wrong with destroying script

 #pragma strict
 var CUBE_1 : GameObject;
 
 function OnCollisionEnter (col : Collision)
 {
     if(col.gameObject.name == "CUBE_d_1")
     {
         Destroy(col.gameObject);
         Destroy(CUBE_1);
     }
 }

This is scrpit what remove CUBE_1 and CUBE_d_1 from scene if happen collison between fpc (this is script is attached to fpc) and CUBE_d_1. But something is wrong. Can you tell me what? It normally destroy CUBE_d_1 when happen collsion, but not destroy CUBE_1...