I more-or-less understand how and when an airbag in inflated and its purpose. But I am wondering (and no one seems to talk about it) what happens to the steering wheel hub/cover that hides the airbag when the bag inflates?

I mean, does the wheel cover/hub flip open when the bag inflates? Does the cover fly off? Or does it tear/get ripped by the exploding air bag? Wouldn't that be risky because our face might get hit by flying shrapnel (like the car logo or bits of plastic)?