how i can stop the animator to play trigger animation?

hey guys , i have an enemy script that detect the distance to the player and do actions…so when the enemy health is <= 0 i want him to die …if(health<=0){ animator.SetTrigger(“die”)},
the problem i have is the enemy is keep playing die animation, i know the problem is the enemy is keep checking the distance to the player but i dont know how to solve this
here is the script:
using UnityEngine;
using System.Collections;

public class enenyscript : MonoBehaviour {
public Transform player;
Animator anim;
public float inrange;
public CharacterController cc;
public float speed;
public int health;
public float destroytime;

// Use this for initialization
void Start () {
    anim = GetComponent<Animator>();
  
    
}

// Update is called once per frame
void Update ()
{
    if(inRange())
    {
        transform.LookAt(player.position);
        anim.SetBool("attack",true);
        
       
        
    }
    else if(!inRange())
    {
        Chase();
        anim.SetBool("attack",false);
        
    }
    

}

bool inRange()
{
    if (Vector3.Distance(transform.position, player.position) <=inrange)
    {
        return true;
    }
    else
    {
        return false;
    }

}

void Chase()
{
    transform.LookAt(player.position);
    cc.SimpleMove(transform.forward * speed);
    anim.SetFloat("Speed",1);
   

}

 
public void gethit(int damage)
{
    health = health - damage;
    if(health<0)
    {
        health = 0;
        anim.SetTrigger("die");

        
       

    }
}



void OnMouseOver()
{
    playercombat.opponent = transform;
}

}

Check your update function…

if(enemy == alive)
{
// do your stuff…
}
else
{
// do nothing, since the enemy is dead…
}