It pierced a quarter inch of steel. With another car, that's enough force to have easily penetrated the passenger cabin and possibly skewered someone. We used to build cars to survive accidents. While there was some success there, unfortunetly the car got mushed up inside. Completely preventing fires do to collision is impossible. No matter how good, the engineers can not envision every scenario, and then budget constraints are a reality. So we take the best steps to preventing them, and design systems to protect the occupants when they do happen.