It is now 20 years since Formula 1 last suffered a fatality during a race when Ayrton Senna died in a crash at the San Marino Grand Prix, but four-time world champion Sebastian Vettel says the inherent danger in the sport cannot be underestimated.

"Formula 1 is safer today but it is still not completely safe because there is still so much that can happen," Vettel said. Despite the increase in safety measures since the death of Senna on May 1, 1994 - and that of Roland Ratzenberger, who died a day earlier in qualifying at the same Grand Prix - Vettel warned: "You must never feel too safe."

Drivers now have head and neck protection, which some feel could have saved Ratzenberger 20 years ago.

Developments have been made in crash tests, larger cockpits with removable seats, better helmets to protect drivers and making the tracks safer.


But a sport such as Formula 1 can never be completely safe. In 2009, Felipe Massa suffered a severe eye injury when a metal spring broke off another car and struck him in the head.

The battle for driver safety remains a core task even 20 years after the death of Ayrton Senna.