diff --git a/leaflet-core.html b/leaflet-core.html
index 1785909..0afcfaf 100644
--- a/leaflet-core.html
+++ b/leaflet-core.html
@@ -723,7 +723,8 @@
 		},
 
 		detached: function() {
-			this._mutationObserver.disconnect();
+			if(this._mutationObserver)
+				this._mutationObserver.disconnect();
 		},
 
 		_viewChanged: function(newValue, oldValue) {
diff --git a/leaflet-layer-group.html b/leaflet-layer-group.html
index 98d8b5f..d150615 100644
--- a/leaflet-layer-group.html
+++ b/leaflet-layer-group.html
@@ -5,9 +5,9 @@
 
 ##### Example
 
-    <leaflet-layer-group>
-        <leaflet-marker latitude="51.505" longitude="-0.09"> </leaflet-marker>
-    </leaflet-layer-group>
+	<leaflet-layer-group>
+	    <leaflet-marker latitude="51.505" longitude="-0.09"> </leaflet-marker>
+	</leaflet-layer-group>
 
 
 @element leaflet-layer-group
@@ -17,7 +17,7 @@
 -->
 
 <dom-module id="leaflet-layer-group">
-	<template>
+	<template><content></content>
 	</template>
 </dom-module>
 
@@ -31,27 +31,37 @@
 			container: {
 				type: Object,
 				observer: '_containerChanged'
-			}	
+			},
+			fitMapToBounds : {
+				type: Boolean,
+				value: false
+			}
 		},
 
-		ready: function() {
+		resetMutationObserver : function() {
 			this._mutationObserver = new MutationObserver(this.registerContainerOnChildren.bind(this));
 			this._mutationObserver.observe(this, {childList: true});
 		},
 	
 		_containerChanged: function() {
 			if (this.container) {
-				var feature = L.layerGroup()
+				var feature = L.layerGroup();
 				this.feature = feature;
 				this.feature.addTo(this.container);
-				this.registerContaierOnChildren();
+				this.registerContainerOnChildren();
 			}
 		},
 
-		registerContaierOnChildren: function() {
+		registerContainerOnChildren: function() {
+			this.resetMutationObserver();
 			for (var i = 0; i < this.children.length; i++) {
 				this.children[i].container = this.feature;
 			}
+			if(this.fitMapToBounds && this.container!=null && this.feature!=null) {
+				var layers = this.feature.getLayers();
+				if(layers.length>0)
+					this.container.fitBounds(L.featureGroup(layers).getBounds());
+			}
 		},
 		
 		detached: function() {