When was the last time the death of a sports star affected people around the world the way Ayrton Senna's did? The impact was felt most keenly by his immediate family - which is to say 160 million Brazilians for whom he embodied the best elements of nationhood, and who gave him a funeral fit for a president. But the sadness and disbelief extended far beyond the boundaries of his country or his sport. To his fellow Grand Prix drivers, men who live with the permanent likelihood of death, Senna had seemed to be invulnerable. Many millions who merely watched on televison had seen him the same way. Ayrton Senna's sudden death posed the question of the extent to which a person may be allowed to put their lives - and sometimes those of others - at risk for what is merely a sport.