Index: Ringtoets/ClosingStructures/src/Ringtoets.ClosingStructures.Plugin/ClosingStructuresPlugin.cs
===================================================================
diff -u -r4791bede4dd0cef468ade017c236dc1efc64b163 -r151cae0869d7173dd61dfb4d85f6f2b545222e1f
--- Ringtoets/ClosingStructures/src/Ringtoets.ClosingStructures.Plugin/ClosingStructuresPlugin.cs	(.../ClosingStructuresPlugin.cs)	(revision 4791bede4dd0cef468ade017c236dc1efc64b163)
+++ Ringtoets/ClosingStructures/src/Ringtoets.ClosingStructures.Plugin/ClosingStructuresPlugin.cs	(.../ClosingStructuresPlugin.cs)	(revision 151cae0869d7173dd61dfb4d85f6f2b545222e1f)
@@ -398,8 +398,14 @@
             return ValidateAllDataAvailableAndGetErrorMessage(context.AssessmentSection, context.FailureMechanism);
         }
 
-        private static void CalculationContextOnNodeRemoved(ClosingStructuresCalculationContext arg1, object arg2)
+        private static void CalculationContextOnNodeRemoved(ClosingStructuresCalculationContext context, object parentData)
         {
+            var calculationGroupContext = parentData as ClosingStructuresCalculationGroupContext;
+            if (calculationGroupContext != null)
+            {
+                calculationGroupContext.WrappedData.Children.Remove(context.WrappedData);
+                calculationGroupContext.NotifyObservers();
+            }
         }
 
         #endregion
Index: Ringtoets/ClosingStructures/test/Ringtoets.ClosingStructures.Forms.Test/TreeNodeInfos/ClosingStructuresCalculationContextTreeNodeInfoTest.cs
===================================================================
diff -u -r4791bede4dd0cef468ade017c236dc1efc64b163 -r151cae0869d7173dd61dfb4d85f6f2b545222e1f
--- Ringtoets/ClosingStructures/test/Ringtoets.ClosingStructures.Forms.Test/TreeNodeInfos/ClosingStructuresCalculationContextTreeNodeInfoTest.cs	(.../ClosingStructuresCalculationContextTreeNodeInfoTest.cs)	(revision 4791bede4dd0cef468ade017c236dc1efc64b163)
+++ Ringtoets/ClosingStructures/test/Ringtoets.ClosingStructures.Forms.Test/TreeNodeInfos/ClosingStructuresCalculationContextTreeNodeInfoTest.cs	(.../ClosingStructuresCalculationContextTreeNodeInfoTest.cs)	(revision 151cae0869d7173dd61dfb4d85f6f2b545222e1f)
@@ -21,6 +21,7 @@
 
 using System.Linq;
 using System.Windows.Forms;
+using Core.Common.Base;
 using Core.Common.Controls.TreeView;
 using Core.Common.Gui;
 using Core.Common.Gui.ContextMenu;
@@ -33,6 +34,7 @@
 using Ringtoets.ClosingStructures.Plugin;
 using Ringtoets.Common.Data;
 using Ringtoets.Common.Data.AssessmentSection;
+using Ringtoets.Common.Data.Calculation;
 using Ringtoets.Common.Data.Probability;
 using Ringtoets.Common.Forms.PresentationObjects;
 using RingtoetsCommonFormsResources = Ringtoets.Common.Forms.Properties.Resources;
@@ -252,6 +254,42 @@
             }
         }
 
+        [Test]
+        public void OnNodeRemoved_ParentIsCalculationGroupContext_RemoveCalculationFromGroup()
+        {
+            // Setup
+            var group = new CalculationGroup();
+            var failureMechanism = new ClosingStructuresFailureMechanism();
+            var elementToBeRemoved = new ClosingStructuresCalculation();
+            var observerMock = mocks.StrictMock<IObserver>();
+            var assessmentSectionMock = mocks.Stub<IAssessmentSection>();
+            var calculationContext = new ClosingStructuresCalculationContext(elementToBeRemoved,
+                                                                            failureMechanism,
+                                                                            assessmentSectionMock);
+            var groupContext = new ClosingStructuresCalculationGroupContext(group,
+                                                                           failureMechanism,
+                                                                           assessmentSectionMock);
+
+            observerMock.Expect(o => o.UpdateObserver());
+
+            mocks.ReplayAll();
+
+            group.Children.Add(elementToBeRemoved);
+            group.Children.Add(new ClosingStructuresCalculation());
+            group.Attach(observerMock);
+
+            // Precondition
+            Assert.IsTrue(info.CanRemove(calculationContext, groupContext));
+            Assert.AreEqual(2, group.Children.Count);
+
+            // Call
+            info.OnNodeRemoved(calculationContext, groupContext);
+
+            // Assert
+            Assert.AreEqual(1, group.Children.Count);
+            CollectionAssert.DoesNotContain(group.Children, elementToBeRemoved);
+        }
+
         private class TestClosingStructuresOutput : ProbabilityAssessmentOutput
         {
             public TestClosingStructuresOutput() : base(0, 0, 0, 0, 0) { }