Notes:
Twenty-five riders started the Trofeo Italia 250 Grand Prix race, held at Monza on Sunday, 21 July 1991. While approaching the so-called Prima Variante along the main straight of Monza, Wilmer Marsigli was involved in a multiple pile-up. He fell down with other ten riders.

After colliding with another machine, his fuel tank was ruptured, dumping a large amount of fuel on him. Fire erupted beneath the wreckages, it took several minutes to be extinguished. Marsigli received severe burns and was taken to Niguarda hospital in Milan, but later being the state of his health still worrying, the family decided to transport the unfortunate rider to Parma hospital. He succumbed to his injuries twelve days later, on Friday, 02 August 1991. He was 23.

The accident occurred in the chicane that in consequence of this tragedy, was changed by FIA-Fédération Internationale de l'Automobile.

A press campaign started in Italy about the capability of the marshals and course workers on duty at Monza the day of the accident, who were using inadequate equipment to fight a fuel fire. It continued to burn until a journalist arrived to the scene of the accident with another fire extinguisher. Wilmer Marsigli was badly burned, also wearing synthetic clothing. Twelve years later his family won a lawsuit against the Monza circuit and obtained a compensation.

Wilmer Marsigli was a 23-year-old from Bologna, Italy. He managed a famous motorcycle workshop in via Bernardi, Bologna, with his older brothers Walter and William Marsigli, who also were talented racing riders. He was a member of the Moto Club Spoleto. After his death, his team organized the annual "Trofeo Wilmer Marsigli" at Magione circuit, in his memory.

• Magazine Rombo, issue 08 August 1991, page 51.
• Newspaper Corriere della Sera (Milan, Italy) issue of Wednesday, 06 May 1992, page 41, article "Motociclista mori' in gara a Monza, nel videotape la verita' sui soccorsi".
• Website Il Resto del Carlino, article "Morì in pista, risarcita la famiglia", page http://ilrestodelcarlino.quotidiano.net/chan/24/1:4565026:/2003/07/22 and page http://ilrestodelcarlino.quotidiano.net/chan/24/7:4565049:/2003/07/22 .
• Website Ozebook - Motorcycle Racing Memoriam Site, page http://www.ozebook.com/gpwin/documents/24.html .
• Website Moto Games, article "Wilmer Marsigli: Il fuoco fu fatale dopo la caduta alla 1° variante di Monza", page http://www.motogames.it/2012/08/01/wilmer-marsigli-il-fuoco-fu-fatale-dopo-la-caduta-alla-1%C2%B0-variante-di-monza/ .