Marionette issue with collection.remove

Marionette collectionview not autmatically re-rendering when removing model from collection

HTML

<script src="http://underscorejs.org/underscore.js"></script>
<script src="http://backbonejs.org/backbone.js"></script>
<script src="http://marionettejs.com/downloads/backbone.marionette.js"></script>
<header>
<h1>A Marionette Playground</h1>
</header>

<article id="main">
</article>

<script type="text/html" id="sample-template">
    put some content <%= contentPlacement %>. <a href="#" id="remove">Remove</a>
</script>

JavaScript

// Define the app and a region to show content
// -------------------------------------------

var App = new Marionette.Application();

App.addRegions({
    "mainRegion": "#main" 
});

// Create a module to contain some functionality
// ---------------------------------------------

App.module("SampleModule", function(Mod, App, Backbone, Marionette, $, _){

    var MyModel = Backbone.Model.extend({
        
    });
    var MyCollection = Backbone.Collection.extend({
        Model: MyModel
    });
    // Define a view to show
    // ---------------------
    
    var MainView = Marionette.ItemView.extend({
        template: "#sample-template",
        triggers :{
            "click #remove" : "property:remove"
        },
    });
    
    var CollectionView = Marionette.CollectionView.extend({
        itemView: MainView,
        initialize: function(){
            this.on("itemview:property:remove", function(view, model){
                alert(this.collection.length);
                this.collection.remove(view.model);
                alert(this.collection.length);
            });
        }
    });
    
    // Define a controller to run this module
    // --------------------------------------
    
    var Controller = Marionette.Controller.extend({
        
        initialize: function(options){
            this.region = options.region
        },
        
        show: function(){
            var collection = new MyCollection([
                {contentPlacement: "1"},
                {contentPlacement: "2"}
            ]);
    
            var view = new CollectionView({
                collection: collection    
            });
            
            this.region.show(view);
        }
        
    });
    

    // Initialize this module when the app starts
    // ------------------------------------------
    
    Mod.addInitializer(function(){
        Mod.controller = new Controller({
            region: App.mainRegion
        });
       ...