What are the family's liabilities if my parents, who should not be driving, cause an accident?

Both of my parents are 81 and are not well, one with mini-strokes leaving him with memory issues and my mother has vision issues and is very argumentative. They are both still driving which worries me as my mother can't see very well and my father has literally gotten lost and couldn't find his way back home. I worry about something happening to him or worse him having an accident where he hurts someone else. My mom won't take away the keys. Should something happen, what are the liabilities for the whole family?