Unable to destroy and instantiate multiple objects in succession?

I am trying to make a object#1 that will destroy itself and have object#2 (a different prefab) instantiate in it's place, and then repeat. Right now my code will destroy the first object and instantiate the second but then will not repeat the sequence- it instantiates the second object and then the same code will not continue the loop of deleting and replacing an object with another object after the first time object#1 gets replaced. Here is the code:

 using UnityEngine;
 using System.Collections;

public class raisingBlock : MonoBehaviour {

 public Transform RaisingBlock;
 public GameObject lava1;
 public GameObject raisedBlock1;
 public GameObject loweredBlock1;
 public bool raisingBlockLoop1 = true;

 void Start()
 {

     StartCoroutine("MyEvent");
 }

     private IEnumerator MyEvent()
     {
     while(raisingBlockLoop1 == true)
         {
             yield return new WaitForSeconds(2f);
         Destroy(this.gameObject); 
         Instantiate(lava1,this.transform.position,Quaternion.identity);
         yield return new WaitForSeconds(2f);
         Destroy(this.gameObject); 
         Instantiate(raisedBlock1,this.transform.position,Quaternion.identity);
         yield return new WaitForSeconds(2f);
         Destroy(this.gameObject); 



             //            gameObject.GetComponent<SpriteRenderer>().sprite = Resources.Load<Sprite>("loweredBlock1");
             //            yield return new WaitForSeconds(4f);
             //            gameObject.GetComponent<BoxCollider2D>().enabled = true;// wait half a second
             //            gameObject.GetComponent<SpriteRenderer>().sprite = Resources.Load<Sprite>("lava1");
             //            yield return new WaitForSeconds(4f);
             //            gameObject.GetComponent<BoxCollider2D>().enabled = true;// wait half a second
             //            gameObject.GetComponent<SpriteRenderer>().sprite = Resources.Load<Sprite>("raisedBlock1");


         }
     }

}