well, many things can happen. for example, in the first part (which you haven't watched yet), when naruto is learning the rasengan and is looking for tsunade, he almost dies in the fight with kabuto & orochimaru. when "the lights go off" for naruto, the lights went off for the kyuubi too. So, i think that if the jinchuuriki still has the tailed beast sealed in them and the jinchuuriki is about to die, so does the beast. That's why when the akatsuki go look for the jinchuuriki, they cannot kill them, only knock them out, because if they are dead, you can't "steal" the beast.