Strange Debug.Break() behavior

This is my script attached to an object:

 function OnCollisionEnter(collision : Collision) {
 
 if (collision.gameObject.tag != "Trigger") {
     Debug.Break();
     Destroy(rigidbody);
     Destroy(collider);        

     // etc etc
         
     while (true) {
         if (!audio.isPlaying) break;
         yield;
     }

     // etc etc
 
     Debug.Log("Reached end of script");
     Destroy(gameObject);
 }

}

The script runs through to it's end, with each print appearing in the console, however the Debug.Break(); does not cause the editor to pause, it only pauses after Destroy(gameObject); is performed.

Any ideas?