Redirecting to error state from action in Ember.js

While writing my first app in Ember.js I I ran into a problem where I wanted to execute an action through calling some API with jQuery. When this call fails, I want the page to be redirected to the error state.

My code

I've been trying to get my head around this one. I created an action like this:

Contributionkeeper.RepositoriesController = Ember.Controller.extend({
  actions: {
    delete: function(repo) {
      Ember.$.ajax({ 
        url: '...', 
        success: function(data) { }, 
        error: function() { 
          //TODO: Raise error
        });
    }
  }
});

Question

I want the application to navigate to an error substate. How can I fix this?