While traveling in traffic southbound on I-95 @ 75 mph in palm beach county there was a shift of the right rear to the right. I adjusted to maintain control presuming possible high winds on the road. Upon accelerating there was no power, therefore I applied brakes to coast to the right shoulder and put the car in park (automobile was still moving until it came to a complete stop). Looking around the vehicle, everything seemed normal; no leakage of liquids/fluids, no skid marks, no foreign debris, etc. While auto was being put upon the flat bed for tow, there was a cylinder-shaped piece located on the ground near the tow truck. I noticed the item, but didn't think much of it at the time. After the car was towed to my residence 40 miles away from the incident and before being released from flat bed tow truck; the right rear wheel/tire was projecting about 45 degrees out from rear fender weld. The car had to be jacked up and the wheel/tire had to be held in place by hand and rotated slowly off the ramp. Upon further investigation, it is noticed that only the top portion of the brake calipher assembly was holding the wheel all along. The jack had to be left in place because the wheel/tire was not stable. Also, grease was spread throughout the interior wheel; 3 wheel bearings seemed missing, the axle was completely disengaged (clean-cut through) from the portion of the wheel/tire assembly, including the wheel break cylinder and the other portion of the axel was lodged in the axle/differential housing unit. The area around the ring shelve had a rust-like color (therefore, assuming that a high degree of heat was a factor in the structural/material breakdown), portions of the wheel were magnetized with metal shavings within grease upon the wheel drum housing; broken/crushed bearings parts and the axel completely cut off at the wheel assembly area. Mechanics were puzzled.

- Tamarac, FL, USA