Saturday 8th September 1923
Ugo Sivocci (38), winner of the 1923 Targa Florio, died during practice for the Italian Grand Prix at Monza, when his Alfa Romeo left the track and crashed into a tree. On the same day of the accident, a press release of the engineer Nicola Romeo announced the withdrawal of other Alfa Romeo cars competing. Sivocci’s car was painted with the green cloverleaf on a white background that was to become Alfa’s good luck token. His car was carrying number 17, which was never again assigned to Italian racing cars.