This summer a boat trailer ahead of us starting smoking from the right side tire and then it came off completely and took off and passed the trailer as it was pulling over, and continued onto the other side of the road. It went for several hundred yards before going into a nearby field. Good thing there wasn't a car coming. Locally there was a FedEx truck that burnt the bearings, the wheel came off and caught fire the dried grass along the road. It had 1/2 million miles on it, typical maintenance I suppose.