Raycasting not adding force to rigidbody

As the title says, I'm trying to make a raycast addforce to a rigidbody. It's colliding and giving me the message (Hit a Box!) but not adding force at all. the box itself has a box collider, a rigidbody, and uses gravity. Here's the code for the shooting part:

 var force = 2000;
 var direction = transform.forward;

 function Update(){
     var forward : Vector3 = transform.TransformDirection(Vector3.forward) * 10;
 
 if (Input.GetButtonDown("Fire1")){
 if (shootEnabled == true){
     if (Bullets > 0){
         if (Clip > 0){

             Shoot();
             Bullets -= 1;
       }
    }
 }
 }
 
 if (Bullets == 0){
     if (Clip >= 1){
         Clip -= 1;
         Bullets = MaxBullets;
     }
     if (Clip == 0){
         Bullets = 0;
     }
 }
 OnGUI();
 }

 function Shoot(){
 //var ray = Camera.main.ScreenPointToRay (Vector3(Screen.width/2,Screen.height/2,0));
 //var hit: RaycastHit; // do a raycast
 var cam : Transform = Camera.main.transform;
 var ray = new Ray(cam.position, cam.forward);
 var hit : RaycastHit;
 
 var trf = transform; // a little optimization
 MuzzleFlashOn();
 
     if(Physics.Raycast (ray, hit, 1000)){
     var rot = Quaternion.FromToRotation(Vector3.up, hit.normal);
     audio.PlayOneShot(shotSound); // play the shot sound...
              
         if(hit.collider.gameObject.tag == "Box"){
             Debug.Log ("Hit A Box!");
             if (sparksPrefab) Instantiate(sparksPrefab, hit.point, rot); 
             hit.rigidbody.AddForceAtPosition(force * direction, hit.point);
     }
         if(hit.collider.gameObject.tag == "Enemy"){
             Debug.Log ("Hit A Enemy!");
             if (sparksPrefab) Instantiate(sparksPrefab, hit.point, rot);
     }  else {            
         if (sparksPrefab) Instantiate(sparksPrefab, hit.point, rot);
         Debug.Log ("Hit Other!");
     }
     shootEnabled = false;
     yield WaitForSeconds(shotInterval);
     shootEnabled = true;
     
     }
     }