In the subsequent Royal Automobile Club (the UK organising and regulatory representative of the FIA at the time) investigation, it was discovered that the crash itself caused non-fatal injuries but Siffert had rather been killed by smoke inhalation.

On-board fire extinguishers (using BCF—Bromochlorodifluoromethane, an aircraft product) became mandatory and also piped air directly into the drivers' helmets.

Hailwood's car was deemed unfit to continue, but Peterson rejoined the race, albeit nearly a lap down.

Approaching Hawthorn Bend at high speed on lap 15, Siffert's BRM suffered a mechanical failure which pitched it across the track into an earth bank.

The car rolled over and caught fire, trapping Siffert underneath, and he died of smoke inhalation in the flames.