c# destroy gameobject on 0 hp

i have a simple destroy script but i cant figure out how to change it from a key stroke destroy. insted i want when the enemyhealth hits 0 to destroy
(and if possible only destroy the one in player area)

destroy script

using UnityEngine;
using System.Collections;

public class EnemyDeath : MonoBehaviour
{
void Update ()
{
if(Input.GetKey(KeyCode.Space))
{
Destroy(gameObject);
}
}
}

using UnityEngine;
using System.Collections;

public class EnemyDeath : MonoBehaviour
{
	void Update()
	{ 
		if(Stats.health <= 0) // If stats class' health var <= 0, destroy enemy object
			Destroy(this.gameObject); 
	}
}

public class Stats
// New class to store variables about your enemy
{
	public int health; // Health variable
}

Like @tw1st3d said, the only thing you have to do before destroy the enemy is create a condition like that,

if( hp <= 0)
destroy(this.gameobject);