Removing all view except login page


I’ve made an Ionic 2 Pj:
> ionic starts project1 tabs --v2

Then I’ve added a page and a provider:
> ionic g provider authService
> ionic g page loginPage

I set root after logging in successful:
> this.nav.setRoot(TabsPage)

It’s navigated to HomePage. I set root when logging out:
> this.nav.setRoot(LoginPage)

The problem is when I logged out the tab panel still appeared and all the page seemed to still can be navigated to. How can I destruct all page when I log out and hide tabs panel too?