The really sad thing is that he was able to move his feet when the medics got to him after the accident - his spinal cord was still intact then. Somewhere between the accident and the hospital, it was severed. Its the classic one they use in training docs to deal with head and neck injuries.
Sad to hear he's died - the Superman films are such a part of my childhood! He always said he was sure he would walk again. Maybe now he is - I hope so!