If that happens, Hillary will get cut out of the race. Not sure what happens next. Martial law? Kaine taking over the Presidential ticket? Bernie replacing Hillary? Who knows...
But, if Hillary is removed in such a way to generate sympathy - some sort of terminal disease, or Bill vists Ft. Marcy Park - I'd be worried that Dems would take the election.
It’s too late for the dems to recover.
Hillary cares no more for the D party than she cares for the country. Rather than give up her nomination, she would see the party destroyed.