Unity 5 How to destroy Enemy and not Ground in C#

 using UnityEngine;
 using System.Collections;
 
 public class Attack : MonoBehaviour
 {
 
     public float fireRate = 0;
     public float damage = 10;
     public LayerMask whatToHit;
 
     float timeToFire = 0;
     Transform firePoint;
 
     // Use this for initialization
     void Awake()
     {
         firePoint = transform.FindChild("FirePoint");
         if (firePoint == null)
         {
             Debug.LogError("No firepoint");
         }
     }
 
     // Update is called once per frame
     void Update()
     {
         if (fireRate == 0)
         {
             if (Input.GetButtonDown("Fire1"))
             {
                 Shoot();
             }
         }
         else
         {
             if (Input.GetButton("Fire1") && Time.time > timeToFire)
             {
                 timeToFire = Time.time + 1 / fireRate;
                 Shoot();
             }
         }
     }
 
     void Shoot()
     {
         Vector2 mousePosition = new Vector2(Camera.main.ScreenToWorldPoint(Input.mousePosition).x, Camera.main.ScreenToWorldPoint(Input.mousePosition).y);
         Vector2 firePointPosition = new Vector2(firePoint.position.x, firePoint.position.y);
         RaycastHit2D hit = Physics2D.Raycast(firePointPosition, mousePosition - firePointPosition, 500, whatToHit);
         Debug.DrawLine(firePointPosition, (mousePosition - firePointPosition) * 100000, Color.yellow);
         if (hit.collider != null)
         {
             Debug.DrawLine(firePointPosition, hit.point, Color.red);
             Debug.Log("Hit " + hit.collider.name + " and did " + damage + " damage.");
         }
 
         if (hit.collider == (gameObject.CompareTag("Ground")))
         {
             Debug.Log("Hit ground");
         } else
         {
             GameObject.Destroy(hit.collider.gameObject);
         }
         
     }
 }