The 24-lap race on Sunday in Barcelona was halted after two major incidents in the first two corners, one of which involved Bagnaia.
The reigning champion got the holeshot from pole position and crashed on his own as he came around Turn 2.
Bagnaia was then sickeningly struck by KTM’s Brad Binder, who could do nothing to avoid running over the Ducati rider’s leg.
The race was immediately red-flagged as Bagnaia received instant medical attention.
He was taken to the medical centre by ambulance and was reported as conscious before being transferred to Hospital General de Catalunya.
The first crash was instigated by Ducati’s Enea Bastianini, who crashed on the way into Turn 1, triggering a collision with Pramac Ducati’s Johann Zarco.
This then involved both Gresini Ducati’s of Fabio Di Giannantonio and Alex Marquez, and the VR46 Ducati of Marco Bezzecchi.
🚩 RED FLAG 🚩
— MotoGP™🏁 (@MotoGP) September 3, 2023
Multiple rider incident at Turn 1 🛑#CatalanGP 🏁 pic.twitter.com/xVVZtHopGi
Bastianini did not take the restart having gone to the medical centre for checks, meaning no factory Ducati team rider will be present in the Catalan GP.
He was then transferred to hospital alongside his team-mate.
It is not clear yet how the stewards will impose his long lap penalty, as the punishment was handed out for this race.
All the other riders involved appeared to walk away unscathed.
A quick restart procedure began at 2:21pm local time, where pitlane was open for 60 seconds.
Riders made their way to the grid, where they were met by one mechanic before being sent off on a sighting lap.
The race will take place over 23 laps.