Google Maps being wrong is not dangerous. It's an inconvenience. There can be absolutely no expectation that Google Maps is correct. Routes are generated automatically by complex algorithms working on imperfect data. I'm sure if anyone gave a shit they'd find this type of warning in some TOS or whatever.
People driving recklessly is dangerous. If you drive off a collapsed bridge you were driving recklessly. There is no way that happens if you drive responsibly. You are literally trying to drive onto a bridge that does not exist, you can't see any bridge there but you are trying to drive onto it anyway. There are two ways I can see this happening. Either you were looking away (generally phone) for multiple seconds without properly looking ahead, or you were going much much faster than you should given the conditions.
Google can, in my opinion, not be held responsible for reckless drivers who happen to be using their app.