Rear bearings fell out - Cycling

Your hub was miss adjusted, You will need to replace the bearings, the easiest is to get caged bearings and use a good lithium grease on the bearings. Adjustment of the cones can be frustrating. Find someone who is familiar with cone and bearing adjustment and pay attention to what they use for tools (cone wrenches) and how it is done, so you can do it yourself. This is an item I perform on annual bike tune-ups.