The Wheel Bearing Bolts came loose and began to fall out. One rubbed against the clamp for the axle boot. The driver was alerted to an issue due to a whining noise from the wheel. Unclear if this noise came from the wheel bearing failing due to misalignment caused by added stress on the single remaining bolt or the rubbing of one of the bolts against the axle. Visual inspection showed one of the bolts had almost completely fallen out. Car was towed to a repair shop and wheel bearings and bolts were replaced.