Rear Axle Spindle problems of the 1997 Chevrolet Lumina

My wife was driving our 1997 Chevrolet Lumina sedan (which we have owned since new with no prior damage to vehicle) on her way to work on a local expressway going approximately 65 mph, when without warning the driver's side rear wheel separated from the vehicle. When the shock tower dragged the ground, this caused the vehicle to be thrust left into a concrete center median divider after crossing 2 lanes of traffic, causing major damage to the front and driver's side of the vehicle. Although this was during the morning rush hour, no other vehicle was involved. Upon investigation of the separated wheel, the spindle had failed. The wheel bearings were still nicely greased and free. The brake drum was still attached to the hub with all of the lug nuts completely tightened. My wife lost her job and was off work for over 4 mos. From injuries sustained from this incident. The vehicle was determined to be a total loss by our insurance company. The manufacturer to this point has refused and compensation stemming from the incident.