cant make player die when he falls

so here is my code my problem is that the in the update method some the code that's written isn't working and also i checked if the player is below -16 when he falls and he is pls help

`/okay here it is` / / /it starts here

 using UnityEngine;
 using System.Collections;
 using Photon.Pun;
 using Photon.Realtime;
 
 public class Health : MonoBehaviourPunCallbacks, IPunObservable
 {
     public bool canDie = true;                            
     public int maxHealth = 100;            
     public int currentHealth = 100;    
 
     public Transform transform;
 
     public bool replaceWhenDead = false;        
     public GameObject deadReplacement;            
     public bool makeExplosion = false;            
     public GameObject explosion;                
 
     public bool isPlayer = false;                
     public GameObject deathCam;                    
 
     private bool dead = false;                    
 
     public void OnPhotonSerializeView(PhotonStream stream, PhotonMessageInfo info)
     {
 
         if (stream.IsWriting)
         {
             stream.SendNext(currentHealth);
         }
         else if (stream.IsReading)
         {
             currentHealth = (int)stream.ReceiveNext();
         }
         
 
     }
 
 
         void Start()
       {
         // Initialize the currentHealth variable to the value specified by the user in startingHealth
         currentHealth = maxHealth;
     
       }
 
     void Update() 
     {
         if (transform.position.y <= -16) 
         {
          Die();
         }
     }
     
 
 
 
 
     public void ChangeHealth(int amount)
     {
         // Change the health by the amount specified in the amount variable
         currentHealth += amount;
 
         // If the health runs out, then Die.
         if (currentHealth <= 0 && !dead && canDie)
             Die();
 
         // Make sure that the health never exceeds the maximum health
         else if (currentHealth > maxHealth)
             currentHealth = maxHealth;
     }
 
     IEnumerator Respawn()
     {
         
         transform.Find("Pm").GetComponent<Camera> ().enabled = false;
         transform.position = new Vector3(-3, 1, 19);
         yield return new WaitForSeconds(4);
         transform.Find("Pm").GetComponent<Camera> ().enabled = true;
         currentHealth = maxHealth;
         dead = false;
 
     }
 
 
 
 
     public void Die()
     {
         
 
         // This GameObject is officially dead.  This is used to make sure the Die() function isn't called again
         dead = true;
 
         // Make death effects
         if (replaceWhenDead)
             Instantiate(deadReplacement, transform.position, transform.rotation);
         if (makeExplosion)
             Instantiate(explosion, transform.position, transform.rotation);
 
         if (isPlayer && deathCam != null)
             deathCam.SetActive(true);
 
         // Remove this GameObject from the scene
         if(currentHealth <= 0)
         {
             StartCoroutine(Respawn());
         }
             
         
     
     }
 }