Clunking noises

Just a few days ago, I was riding my dad's bike (mine is still broken...ughh) and I felt a very light "clunking" noise. After a decent time of riding, the bike made a rather large clunk while I was passing an intersection, and the rear wheel stopped moving. I had to have my Dad pick me up, and when I looked at it at home, nothing appeared to be wrong, except the rear brakes which appeared to be lopsided. I moved the brakes back into place, and the wheel did not hit the brakes until a certain point. So I now believe that is an issue with the wheel, and not the brakes. At this point, I didn't really know what was going on, so I rode it until the wheel hit the brake just to see where the noises were coming from, and after the second time of doing so, I heard a really loud clunk, and a bearing fell out. There was also a jagged little piece of metal that fell out from somewhere as well. I don't really know exactly where it's coming from, but I really need to try and figure out how to fix this because I feel awful for somehow breaking my dad's bike. I will post pictures to help out as well. Thanks.