The British Grand Prix was suspended before the end of the first lap after two huge collisions involving multiple drivers on the pit straight resulted in Zhou Guanyu's Alfa Romeo ending up on the wrong side of the tyre barriers at Turn 1.
Emergency crews were immediately in attendance, with Zhou and Williams driver Alex Albon being taken to the medical centre.
Both were cleared of major injuries and released from Coventry Hospital after precautionary checks.
A replay showed Pierre Gasly being pinched between George Russell on one side and Zhou on the other,
with contact between Gasly and Russell pitching the Mercedes of Russell into Zhou's Alfa Romeo.
The energy of the second impact rolled Zhou's car, sending it upside down through the run-off area before it barrel-rolled over the barriers
The Halo was introduced in F1 ahead of the 2018 season but was controversial, with many traditionalists as it was such a big step away from the unprotected look of cars.