One can't stop others gossipping.. but I would say.. .''she really told me nothing.. I am as much in the dark about what happened as you are...'' if something happened in my own family and people wanted to ask.. well those who ask out of concern I believe have a right to know.. who really care but to others I would say '' It's really too painful for me to talk about this. please excuse me.. '' and walk off..and let them think what they want... ''How did the accident happen'' I have no idea.. there are 50 other onlookers, ask them'' I am only passing by here.
Just tell them that you do not know, without being rude to anyone.....gossip is terrible. Do not get caught up in other folks business or let them get into your business.
You never have to answer a question just because somebody asks it. When they are asking you about your business, that's not gossip. It's snooping, prying, probing, etc.
What works for me is just to say "oh I don't know" and act as uncomfortable as I feel in the face of their nosiness. If that doesn't work, I say "I don't know, ask her."
Be evasive, don't let them extract information from you just because they want it.