RACE CAR HITS CROWD; KILLS 80 FRANCE - A black day at the annual Grand Prix; the LeMans classic of sports car speed and endurance. In the second hour of the round the clock motor marathon; a Mercedes crashes into the rear of another car; caroms into the crowd; and explodes. The flaming wreck cuts a 400 yard furrow of death; killing 80; injuring over 100 more - the worst disaster in the annals of auto racing.