diff --git a/Polyhedron/demo/Polyhedron/Scene_c3t3_item.cpp b/Polyhedron/demo/Polyhedron/Scene_c3t3_item.cpp
index 937796bf0cf..08a63e2bf8d 100644
--- a/Polyhedron/demo/Polyhedron/Scene_c3t3_item.cpp
+++ b/Polyhedron/demo/Polyhedron/Scene_c3t3_item.cpp
@@ -280,9 +280,6 @@ struct Scene_c3t3_item_priv {
     invalidate_stats();
   }
   ~Scene_c3t3_item_priv()
-  {
-  }
-  void destroy()
   {
     c3t3.clear();
     tree.clear();
@@ -294,6 +291,7 @@ struct Scene_c3t3_item_priv {
       delete tet_Slider;
     }
   }
+
   void init_default_values() {
     positions_lines.resize(0);
     positions_poly.resize(0);
@@ -531,7 +529,6 @@ Scene_c3t3_item::~Scene_c3t3_item()
 {
   if(d)
   {
-    d->destroy();
     delete d;
     d = NULL;
   }
@@ -2018,9 +2015,17 @@ void Scene_c3t3_item::itemAboutToBeDestroyed(Scene_item *item)
 {
   Scene_item::itemAboutToBeDestroyed(item);
 
-  if(d)
+  if(d && item == this)
   {
-    d->destroy();
+    d->c3t3.clear();
+    d->tree.clear();
+    if(d->frame)
+    {
+      static_cast<CGAL::Three::Viewer_interface*>(QGLViewer::QGLViewerPool().first())->setManipulatedFrame(0);
+      delete d->frame;
+      d->frame = NULL;
+      delete d->tet_Slider;
+    }
     delete d;
     d=0;
   }
diff --git a/Polyhedron/demo/Polyhedron/Scene_c3t3_item.h b/Polyhedron/demo/Polyhedron/Scene_c3t3_item.h
index 390da10691f..a5fbb23568a 100644
--- a/Polyhedron/demo/Polyhedron/Scene_c3t3_item.h
+++ b/Polyhedron/demo/Polyhedron/Scene_c3t3_item.h
@@ -149,7 +149,7 @@ public:
 
   QColor get_histogram_color(const double v) const;
 
-  void itemAboutToBeDestroyed(Scene_item *);
+  void itemAboutToBeDestroyed(Scene_item *) Q_DECL_OVERRIDE;
 
   protected:
     friend struct Scene_c3t3_item_priv;
diff --git a/Polyhedron/demo/Polyhedron/Scene_points_with_normal_item.cpp b/Polyhedron/demo/Polyhedron/Scene_points_with_normal_item.cpp
index f0cdce0798c..e924d47bdfe 100644
--- a/Polyhedron/demo/Polyhedron/Scene_points_with_normal_item.cpp
+++ b/Polyhedron/demo/Polyhedron/Scene_points_with_normal_item.cpp
@@ -877,7 +877,7 @@ int Scene_points_with_normal_item::getPointSliderValue()
 void Scene_points_with_normal_item::itemAboutToBeDestroyed(Scene_item *item)
 {
   Scene_item::itemAboutToBeDestroyed(item);
-  if(d && d->m_points)
+  if(d && d->m_points && item == this)
   {
     delete d->m_points;
     d->m_points = NULL;
diff --git a/Polyhedron/demo/Polyhedron/Scene_points_with_normal_item.h b/Polyhedron/demo/Polyhedron/Scene_points_with_normal_item.h
index 4c32f4f5749..41c938492ef 100644
--- a/Polyhedron/demo/Polyhedron/Scene_points_with_normal_item.h
+++ b/Polyhedron/demo/Polyhedron/Scene_points_with_normal_item.h
@@ -89,7 +89,7 @@ public Q_SLOTS:
   void pointSliderPressed();
   //Set the status of the slider as `released`
   void pointSliderReleased();
-  void itemAboutToBeDestroyed(Scene_item *);
+  void itemAboutToBeDestroyed(Scene_item *) Q_DECL_OVERRIDE;
 
 // Data
 protected:
diff --git a/Polyhedron/demo/Polyhedron/Scene_polygon_soup_item.cpp b/Polyhedron/demo/Polyhedron/Scene_polygon_soup_item.cpp
index edcc6a0854c..cc912635d9a 100644
--- a/Polyhedron/demo/Polyhedron/Scene_polygon_soup_item.cpp
+++ b/Polyhedron/demo/Polyhedron/Scene_polygon_soup_item.cpp
@@ -854,13 +854,12 @@ std::vector<CGAL::Color> Scene_polygon_soup_item::getFColors() const{return d->s
 void Scene_polygon_soup_item::itemAboutToBeDestroyed(Scene_item *item)
 {
   Scene_item::itemAboutToBeDestroyed(item);
- if(d)
- {
-   if(d->soup)
-   {
-     delete d->soup;
-     d->soup=NULL;
-   }
- }
-
+  if(d && item == this)
+  {
+    if(d->soup)
+    {
+      delete d->soup;
+      d->soup=NULL;
+    }
+  }
 }
diff --git a/Polyhedron/demo/Polyhedron/Scene_polygon_soup_item.h b/Polyhedron/demo/Polyhedron/Scene_polygon_soup_item.h
index 9ac9779b2f2..767deb6f3ab 100644
--- a/Polyhedron/demo/Polyhedron/Scene_polygon_soup_item.h
+++ b/Polyhedron/demo/Polyhedron/Scene_polygon_soup_item.h
@@ -151,7 +151,7 @@ public Q_SLOTS:
 
     void setDisplayNonManifoldEdges(const bool);
     bool displayNonManifoldEdges() const;
-    void itemAboutToBeDestroyed(Scene_item *item);
+    void itemAboutToBeDestroyed(Scene_item *item) Q_DECL_OVERRIDE;
 
 protected:
     friend struct Scene_polygon_soup_item_priv;
diff --git a/Polyhedron/demo/Polyhedron/Scene_polyhedron_item.cpp b/Polyhedron/demo/Polyhedron/Scene_polyhedron_item.cpp
index c8679dbcb3d..b439e4bf04f 100644
--- a/Polyhedron/demo/Polyhedron/Scene_polyhedron_item.cpp
+++ b/Polyhedron/demo/Polyhedron/Scene_polyhedron_item.cpp
@@ -94,6 +94,11 @@ struct Scene_polyhedron_item_priv{
   {
     init_default_values();
   }
+  ~Scene_polyhedron_item_priv()
+  {
+    delete poly;
+    delete targeted_id;
+  }
 
   void init_default_values() {
     show_only_feature_edges_m = false;
@@ -123,11 +128,6 @@ struct Scene_polyhedron_item_priv{
                          const bool colors_only) const;
   void init();
   void invalidate_stats();
-  void destroy()
-  {
-    delete poly;
-    delete targeted_id;
-  }
   void* get_aabb_tree();
   QList<Kernel::Triangle_3> triangulate_primitive(Polyhedron::Facet_iterator fit,
                                                   Traits::Vector_3 normal);
@@ -823,7 +823,6 @@ Scene_polyhedron_item::~Scene_polyhedron_item()
     }
     if(d)
     {
-      d->destroy();
       delete d;
       d=NULL;
     }
@@ -1848,9 +1847,8 @@ void Scene_polyhedron_item::set_flat_disabled(bool b)
 void Scene_polyhedron_item::itemAboutToBeDestroyed(Scene_item *item)
 {
   Scene_item::itemAboutToBeDestroyed(item);
-  if(d)
+  if(d && item == this)
   {
-    d->destroy();
     delete d;
     d=NULL;
   }
diff --git a/Polyhedron/demo/Polyhedron/Scene_polyhedron_item.h b/Polyhedron/demo/Polyhedron/Scene_polyhedron_item.h
index f344911dc11..bd3c59a2ab7 100644
--- a/Polyhedron/demo/Polyhedron/Scene_polyhedron_item.h
+++ b/Polyhedron/demo/Polyhedron/Scene_polyhedron_item.h
@@ -142,7 +142,7 @@ public Q_SLOTS:
     void update_facet_indices();
     void update_halfedge_indices();
     void invalidate_aabb_tree();
-    void itemAboutToBeDestroyed(Scene_item *);
+    void itemAboutToBeDestroyed(Scene_item *) Q_DECL_OVERRIDE;
 
 Q_SIGNALS:
     void selection_done();
diff --git a/Polyhedron/demo/Polyhedron/Scene_surface_mesh_item.cpp b/Polyhedron/demo/Polyhedron/Scene_surface_mesh_item.cpp
index 45db04a104d..ddc70183286 100644
--- a/Polyhedron/demo/Polyhedron/Scene_surface_mesh_item.cpp
+++ b/Polyhedron/demo/Polyhedron/Scene_surface_mesh_item.cpp
@@ -646,7 +646,7 @@ void Scene_surface_mesh_item::compute_bbox()const
 void Scene_surface_mesh_item::itemAboutToBeDestroyed(Scene_item *item)
 {
   Scene_item::itemAboutToBeDestroyed(item);
-  if(d && d->smesh_)
+  if(d && d->smesh_ && item == this)
   {
     delete d->smesh_;
     d->smesh_ = NULL;
diff --git a/Polyhedron/demo/Polyhedron/Scene_surface_mesh_item.h b/Polyhedron/demo/Polyhedron/Scene_surface_mesh_item.h
index 42f01f25dbd..e0037cdf4eb 100644
--- a/Polyhedron/demo/Polyhedron/Scene_surface_mesh_item.h
+++ b/Polyhedron/demo/Polyhedron/Scene_surface_mesh_item.h
@@ -53,7 +53,7 @@ public:
   const SMesh* polyhedron() const;
   void compute_bbox()const;
 public Q_SLOTS:
-  void itemAboutToBeDestroyed(Scene_item *);
+  void itemAboutToBeDestroyed(Scene_item *) Q_DECL_OVERRIDE;
   virtual void selection_changed(bool);
 protected:
   friend struct Scene_surface_mesh_item_priv;