Given that there weren't any signs or barriers, it sounds like the local authorities are the ones at fault here. It could even be that that didn't file the proper paperwork to indicate that it collapsed. Google gets it's information from some database and if their sources aren't accurately reporting data as they should, google wouldn't have any way of knowing that the bridge collapsed. Ultimately, hazards like this should be clearly blocked off. Google doesn't have the power to do that.