[8] On 29 May 2021, Dupasquier was involved in a crash with Ayumu Sasaki and Jeremy Alcoba near the end of the day's qualifying session at the Mugello circuit of the Italian Grand Prix (Gran Premio d'Italia) in Scarperia.

[9][11] Dupasquier was taken to Careggi University Hospital, in Florence, Italy,[11] where he underwent "thoracic surgery for a vascular lesion" and was also operated on for a brain injury, according to a statement from the MotoGP World Championship organization.

He died from complications of his injuries on 30 May, aged 19, having been declared brain dead and taken off life support in the morning, surrounded by his family and close friends.

[9] Dupasquier's death was the first during a world championship event since Moto2 rider Luis Salom's fatal crash at Circuit de Barcelona-Catalunya during the second practice session of the 2016 Catalan motorcycle Grand Prix.

Fabio Quartararo, the world championship leader in the MotoGP class at the time, won the event and, in his victory lap, paused at Dupasquier's accident site (turn 9, Arrabbiata 2) and pointed to the sky.