EventManager timing affecting desired GroupBounds output.

I am creating a box collider around a group of brown tiles with some padding. In one case, I am getting too much padding. Experimenting has led me to believe that the padding is due to white tiles that get destroyed moments before. These white tiles shouldn't be in the recalculated brown tile group collider. I have an Event Trigger that destroys all the white tiles before recalculating the bounds of the new grouped objects.

Even though the white tiles are destroyed, their colliders are still used in the recalculation. The console shows that the method containing the Destroy function was executed properly AND THEN the regroup was called.

I do not understand why Unity is creating the box collider of the white tiles, even though they have been destroyed.

Any help in understanding this issue would be helpful. Thanks in advanced.

//PlayedTileState.cs - class that is placed on a brownTileObject

    EventManager.TriggerEvent("DestroySelector");
 
    EventManager.pulledParam = int.Parse(gameObject.transform.root.name);
    EventManager.TriggerEvent("RemakeGroupCollider");

//SelectorTileController.cs - class that is placed on the white tiles

    private void DestroySelfWhenTilePlaced(int useless) {
         Object.Destroy(this.gameObject);
         Debug.Log("Destroyed selector tile on group#" + transform.root.name);
    }
  

//GroupManager.cs - This code is in a class that is placed on a GameManager Empty Object.

    private void makeGroupCollider(int groupNumber){
 
    BoxCollider groupCollider = groupList[groupNumber].AddComponent<BoxCollider>();
    Renderer[] groupColliders = groupList[groupNumber].GetComponentsInChildren<Renderer>();
    Bounds groupBounds = new Bounds(Vector3.zero, Vector3.zero);
 
    foreach(Renderer collider in groupColliders){
        if (groupBounds.extents == Vector3.zero)
            groupBounds = collider.bounds;
        groupBounds.Encapsulate(collider.bounds);
        groupCollider.center = groupBounds.center - groupList[groupNumber].transform.position;
        groupCollider.size = groupBounds.size;
        groupCollider.size = new Vector3(groupCollider.size.x + colliderSizeBuffer, 
           colliderYscale, groupCollider.size.z + colliderSizeBuffer);
        groupCollider.center = new Vector3(groupCollider.center.x, colliderYpos, 
           groupCollider.center.z + colliderZoffset);
        groupCollider.gameObject.layer = 8;
        }
    }
 
     private void RemakeGroupCollider(int groupNumber){
         Destroy(groupList[groupNumber].GetComponent<BoxCollider>());
         makeGroupCollider(groupNumber);
         Debug.Log("Remade Collider on Group#" + groupNumber);
     }