diff --git a/src/main/kotlin/org/sirius/dorm/ObjectManager.kt b/src/main/kotlin/org/sirius/dorm/ObjectManager.kt
index 984f39a..8d69908 100644
--- a/src/main/kotlin/org/sirius/dorm/ObjectManager.kt
+++ b/src/main/kotlin/org/sirius/dorm/ObjectManager.kt
@@ -126,7 +126,7 @@ class ObjectManager() {
     }
 
     fun delete(obj: DataObject) {
-        obj.state?.status = Status.DELETED
+        obj.delete()
     }
 
     // tx
diff --git a/src/main/kotlin/org/sirius/dorm/model/RelationDescriptor.kt b/src/main/kotlin/org/sirius/dorm/model/RelationDescriptor.kt
index 6cb4d26..16a26d5 100644
--- a/src/main/kotlin/org/sirius/dorm/model/RelationDescriptor.kt
+++ b/src/main/kotlin/org/sirius/dorm/model/RelationDescriptor.kt
@@ -47,11 +47,11 @@ open class RelationDescriptor<T:Any>(name: String, val target: String, val multi
     }
 
     override fun defaultValue(): Any? {
-        TODO("Not yet implemented")
+        return null // actually not called at all
     }
 
     override fun validate(value: Any?) {
-        TODO("Not yet implemented")
+        // currently not used
     }
 
     fun isOwner() : Boolean {
diff --git a/src/main/kotlin/org/sirius/dorm/object/Attribute.kt b/src/main/kotlin/org/sirius/dorm/object/Attribute.kt
index 80ea896..38d58ba 100644
--- a/src/main/kotlin/org/sirius/dorm/object/Attribute.kt
+++ b/src/main/kotlin/org/sirius/dorm/object/Attribute.kt
@@ -16,12 +16,12 @@ class Attribute(property: PropertyEntity?, var value: Any) : Property(property)
     override fun set(propertyDescriptor: PropertyDescriptor<Any>, value: Any?) : Boolean {
         propertyDescriptor.validate(value)
 
-        if ( value != this.value ) {
+        return if ( value != this.value ) {
             this.value = value!!
 
-            return true
+            true
         }
-        else return false
+        else false
     }
 
     override fun save(): Any {
diff --git a/src/main/kotlin/org/sirius/dorm/object/DataObject.kt b/src/main/kotlin/org/sirius/dorm/object/DataObject.kt
index 7a175c2..af368f8 100644
--- a/src/main/kotlin/org/sirius/dorm/object/DataObject.kt
+++ b/src/main/kotlin/org/sirius/dorm/object/DataObject.kt
@@ -5,6 +5,7 @@ package org.sirius.dorm.`object`
  * All rights reserved
  */
 import org.sirius.dorm.ObjectManager
+import org.sirius.dorm.model.Cascade
 import org.sirius.dorm.model.ObjectDescriptor
 import org.sirius.dorm.model.PropertyDescriptor
 import org.sirius.dorm.persistence.entity.EntityEntity
@@ -20,6 +21,22 @@ class DataObject(val type: ObjectDescriptor, status: Status, var state : ObjectS
 
     // public
 
+    fun delete() {
+        state?.status = Status.DELETED
+
+        var i = 0
+        for (property in type.properties) {
+            if (!property.isAttribute()) {
+                if (property.asRelation().cascade == Cascade.DELETE) {
+                    if ((values[i] as Relation).isLoaded())
+                        (values[i] as Relation).deleted()
+                }
+            }
+
+            i++
+        }
+    }
+
     var objectManager: ObjectManager
         get() = type.objectManager!!
         set(_) { }
diff --git a/src/main/kotlin/org/sirius/dorm/object/MultiValuedRelation.kt b/src/main/kotlin/org/sirius/dorm/object/MultiValuedRelation.kt
index 671af53..f8c7473 100644
--- a/src/main/kotlin/org/sirius/dorm/object/MultiValuedRelation.kt
+++ b/src/main/kotlin/org/sirius/dorm/object/MultiValuedRelation.kt
@@ -36,10 +36,14 @@ class MultiValuedRelation(relation: RelationDescriptor<*>, status: Status, val o
 
     // implement Relation
 
+    override fun deleted() {
+        for ( obj in this.objects!!)
+            obj.delete()
+    }
+
     override fun isLoaded() : Boolean {
         return objects !== null
     }
-
     override fun addInverse(element: DataObject) {
         this.objects!!.add(element)
     }
diff --git a/src/main/kotlin/org/sirius/dorm/object/Relation.kt b/src/main/kotlin/org/sirius/dorm/object/Relation.kt
index 1c699c0..47e57e2 100644
--- a/src/main/kotlin/org/sirius/dorm/object/Relation.kt
+++ b/src/main/kotlin/org/sirius/dorm/object/Relation.kt
@@ -13,6 +13,8 @@ import org.sirius.dorm.persistence.entity.PropertyEntity
 abstract class Relation(val relation: RelationDescriptor<*>, val targetDescriptor: ObjectDescriptor, property: PropertyEntity?) : Property(property) {
     abstract fun isLoaded(): Boolean
 
+    abstract fun deleted();
+
     abstract fun load(objectManager: ObjectManager)
 
     override fun save(): Any {
diff --git a/src/main/kotlin/org/sirius/dorm/object/SingleValuedRelation.kt b/src/main/kotlin/org/sirius/dorm/object/SingleValuedRelation.kt
index 5e88f97..6f870f4 100644
--- a/src/main/kotlin/org/sirius/dorm/object/SingleValuedRelation.kt
+++ b/src/main/kotlin/org/sirius/dorm/object/SingleValuedRelation.kt
@@ -19,7 +19,11 @@ class SingleValuedRelation(relation: RelationDescriptor<*>, status: Status, val
 
     var target: DataObject? = if ( status == Status.CREATED ) null else DataObject.NONE
 
-    // private
+    // implement Relation
+
+    override fun deleted() {
+        target?.delete()
+    }
 
     override fun load(objectManager: ObjectManager) {
        if ( property !== null) {
@@ -33,8 +37,6 @@ class SingleValuedRelation(relation: RelationDescriptor<*>, status: Status, val
         else target = null
     }
 
-    // implement Relation
-
     override fun isLoaded() : Boolean {
         return target !== DataObject.NONE
     }
@@ -81,8 +83,6 @@ class SingleValuedRelation(relation: RelationDescriptor<*>, status: Status, val
         else return false
     }
 
-    // new
-
     override fun addInverse(element: DataObject) {
         this.target = element
     }