BOLT HOLDING DOWN SPARE TIRE IN TRUNK SHEARED OFF DURING CRASH, CAUSING SPARE TIRE TO BE THROWN AGAINST REAR SEAT BACK. LACK OF REINFORCEMENT CAUSED REAR SEAT BACK TO BOW FORWARD SEVERAL INCHES, KILLING THREE CHILDREN. ALL THREE CHILDREN WERE WEARING SEAT BELTS AND DIED OF INTERNAL INJURIES CAUSED BY FORCE OF THE SEAT BACK SQUEEZING AGAINST FIXED SEAT BELTS. *SLC