do not delete site if it has users or nodes
diff --git a/xos/tosca/resources/xossite.py b/xos/tosca/resources/xossite.py
index fe0e256..a65129a 100644
--- a/xos/tosca/resources/xossite.py
+++ b/xos/tosca/resources/xossite.py
@@ -79,6 +79,12 @@
         if obj.slices.exists():
             self.info("Site %s has active slices; skipping delete" % obj.name)
             return
+        if obj.users.exists():
+            self.info("Site %s has active users; skipping delete" % obj.name)
+            return
+        if obj.nodes.exists():
+            self.info("Site %s has active nodes; skipping delete" % obj.name)
+            return
         super(XOSSite, self).delete(obj)