There won't be. If the self-destruct triggers, then the rocket is 1) already going to cause their deaths, and 2) going to potentially save the lives of people on the ground.
Now, that said, this is why we have escape towers on pods (and the escape rockets around the sides of the Dragon 2). In the case of an emergency, those eject the pod from the rocket so that it can be returned safely, even as the rocket is destroyed.
Now, that said, this is why we have escape towers on pods (and the escape rockets around the sides of the Dragon 2). In the case of an emergency, those eject the pod from the rocket so that it can be returned safely, even as the rocket is destroyed.