diff --git a/Subsurface/Source/Characters/AI/PathFinder.cs b/Subsurface/Source/Characters/AI/PathFinder.cs
index 78846b22c..f01d1b89c 100644
--- a/Subsurface/Source/Characters/AI/PathFinder.cs
+++ b/Subsurface/Source/Characters/AI/PathFinder.cs
@@ -45,6 +45,12 @@ namespace Barotrauma
             var nodes = new Dictionary<int, PathNode>();
             foreach (WayPoint wayPoint in wayPoints)
             {
+                if (wayPoint == null) continue;
+                if (nodes.ContainsKey(wayPoint.ID))
+                {
+                    DebugConsole.ThrowError("Error in PathFinder.GenerateNodes (duplicate ID \"" + wayPoint.ID + "\")");
+                    continue;
+                }
                 nodes.Add(wayPoint.ID, new PathNode(wayPoint));
             }
 
diff --git a/Subsurface/Source/Map/Gap.cs b/Subsurface/Source/Map/Gap.cs
index 0724fae4e..f91af9527 100644
--- a/Subsurface/Source/Map/Gap.cs
+++ b/Subsurface/Source/Map/Gap.cs
@@ -670,19 +670,27 @@ namespace Barotrauma
             return null;
         }
 
-        public override void Remove()
+        public override void ShallowRemove()
         {
-            base.Remove();
-
+            base.ShallowRemove();
             GapList.Remove(this);
 
             foreach (Hull hull in Hull.hullList)
             {
                 hull.ConnectedGaps.Remove(this);
             }
-
         }
 
+        public override void Remove()
+        {
+            base.Remove();
+            GapList.Remove(this);
+
+            foreach (Hull hull in Hull.hullList)
+            {
+                hull.ConnectedGaps.Remove(this);
+            }
+        }
 
         public override void OnMapLoaded()
         {
diff --git a/Subsurface/Source/Map/Hull.cs b/Subsurface/Source/Map/Hull.cs
index d2e30446a..e92b77ad6 100644
--- a/Subsurface/Source/Map/Hull.cs
+++ b/Subsurface/Source/Map/Hull.cs
@@ -332,6 +332,39 @@ namespace Barotrauma
             Pressure = surface;
         }
 
+        public override void ShallowRemove()
+        {
+            base.Remove();
+            hullList.Remove(this);
+
+            if (Submarine == null || (!Submarine.Loading && !Submarine.Unloading))
+            {
+                Item.UpdateHulls();
+                Gap.UpdateHulls();
+            }
+
+            List<FireSource> fireSourcesToRemove = new List<FireSource>(fireSources);
+            foreach (FireSource fireSource in fireSourcesToRemove)
+            {
+                fireSource.Remove();
+            }
+            fireSources.Clear();
+
+            if (soundIndex > -1)
+            {
+                Sounds.SoundManager.Stop(soundIndex);
+                soundIndex = -1;
+            }
+            
+            if (entityGrids != null)
+            {
+                foreach (EntityGrid entityGrid in entityGrids)
+                {
+                    entityGrid.RemoveEntity(this);
+                }
+            }
+        }
+
         public override void Remove()
         {
             base.Remove();
@@ -355,8 +388,7 @@ namespace Barotrauma
                 Sounds.SoundManager.Stop(soundIndex);
                 soundIndex = -1;
             }
-
-            //renderer.Dispose();
+            
             if (entityGrids != null)
             {
                 foreach (EntityGrid entityGrid in entityGrids)
diff --git a/Subsurface/Source/Map/Structure.cs b/Subsurface/Source/Map/Structure.cs
index 39eaa4e99..1ec5885a4 100644
--- a/Subsurface/Source/Map/Structure.cs
+++ b/Subsurface/Source/Map/Structure.cs
@@ -452,7 +452,34 @@ namespace Barotrauma
                 }
             }
         }
-        
+
+        public override void ShallowRemove()
+        {
+            base.ShallowRemove();
+
+            if (WallList.Contains(this)) WallList.Remove(this);
+
+            if (bodies != null)
+            {
+                foreach (Body b in bodies)
+                    GameMain.World.RemoveBody(b);
+            }
+
+            if (sections != null)
+            {
+                foreach (WallSection s in sections)
+                {
+                    if (s.gap != null)
+                    {
+                        s.gap.Remove();
+                        s.gap = null;
+                    }
+                }
+            }
+
+            if (convexHulls != null) convexHulls.ForEach(x => x.Remove());
+        }
+
         public override void Remove()
         {
             base.Remove();
diff --git a/Subsurface/Source/Map/WayPoint.cs b/Subsurface/Source/Map/WayPoint.cs
index fcaf02b5c..8e7417812 100644
--- a/Subsurface/Source/Map/WayPoint.cs
+++ b/Subsurface/Source/Map/WayPoint.cs
@@ -820,6 +820,13 @@ namespace Barotrauma
             }
         }
 
+        public override void ShallowRemove()
+        {
+            base.ShallowRemove();
+
+            WayPointList.Remove(this);
+        }
+
         public override void Remove()
         {
             base.Remove();