Set up better teardown for the ladder view.

app/lib/CocoClass.coffee

@@ -20,6 +20,7 @@ module.exports = class CocoClass
   destroy: ->
     # teardown subscriptions, prevent new ones
     @stopListening?()
+    @off()
     @unsubscribeAll()
     @stopListeningToShortcuts()
     @[key] = undefined for key of @

app/lib/simulator/Simulator.coffee

@@ -10,6 +10,11 @@ module.exports = class Simulator
     @trigger 'statusUpdate', 'Starting simulation!'
     @retryDelayInSeconds = 10
     @taskURL = '/queue/scoring'
+    
+  destroy: ->
+    @off()
+    @cleanupSimulation()
+    # TODO: More teardown?
 
   fetchAndSimulateTask: =>
     @trigger 'statusUpdate', 'Fetching simulation data!'
@@ -99,7 +104,7 @@ module.exports = class Simulator
     @fetchAndSimulateTask()
 
   cleanupSimulation: ->
-    @god.destroy()
+    @god?.destroy()
     @god = null
     @world = null
     @level = null

app/views/kinds/CocoView.coffee

@@ -37,6 +37,7 @@ module.exports = class CocoView extends Backbone.View
 
   destroy: ->
     @stopListening()
+    @off()
     @stopListeningToShortcuts()
     @undelegateEvents() # removes both events and subs
     view.destroy() for id, view of @subviews

app/views/play/ladder_view.coffee

@@ -65,7 +65,7 @@ module.exports = class LadderView extends RootView
     return if @startsLoading
     @insertSubView(@ladderTab = new LadderTabView({}, @level, @sessions))
     @insertSubView(@myMatchesTab = new MyMatchesTabView({}, @level, @sessions))
-    setInterval(@fetchSessionsAndRefreshViews.bind(@), 10000)
+    @refreshInterval = setInterval(@fetchSessionsAndRefreshViews.bind(@), 10000)
     @showPlayModal(document.location.hash[1..]) if document.location.hash and @sessions.loaded
 
   fetchSessionsAndRefreshViews: ->
@@ -119,3 +119,8 @@ module.exports = class LadderView extends RootView
     session = (s for s in @sessions.models when s.get('team') is teamID)[0]
     modal = new LadderPlayModal({}, @level, session, teamID)
     @openModalView modal
+    
+  destroy: ->
+    clearInterval @refreshInterval
+    @simulator.destroy()
+    super()