Cannot detection collision

Greetings, I'm scripting a sword hit to apply damage. The problem is that Unity does not detect any collision.

Here's the test script,

     var damageAmount = 20;
 var isHitting : boolean = false;
 
 function OnCollisionEnter (collision : Collision) {
     isHitting = true;
     
     if (collision.gameObject.GetComponent(Tagger).canBeHit == true){
         collision.gameObject.SendMessage("applyDamage", damageAmount, SendMessageOptions.DontRequireReceiver);
     }
 
 }

For some weird reasons, the isHitting boolean does not turn true. Both my object that have the script and the one I hit have a collider.