Weapon Collision

Ok so i have a player, a weapon(sword) and an enemy. The sword is attached as a child to the hand bone of the player and has a box collider. I want to detect collisions with the enemy so i can kill it.

using UnityEngine;
using System.Collections;

public class WeaponCollision : MonoBehaviour {

	void Update () {
	}

	void OnCollisionEnter(Collision col) {
		Debug.Log ("Collision");
		if (col.gameObject.tag == "Enemy") {
			Destroy(col.gameObject);
		}
	}
}

this script is attached to the weapon object, but its not working, the “Collision” is not being logged either.

Ok, i tried using the OnTriggerEnter method and it’s working.