The tragic events of the 1994 Imola race sparked the biggest safety revolution in Formula 1 history.
Ayrton Senna is remembered fondly as a three-time F1 champion and one of the greatest drivers ever to grace the sport. But perhaps the biggest legacy left by the deaths of the Brazilian and Roland Ratzenberger that weekend are the changes that have saved so many lives since.
Professor Sid Watkins, the head of the F1 medical team at the time, had been powerless to help either of them. But he had saved one life that weekend, removing Rubens Barrichello's tongue from his throat after his crash on the Friday.
Watkins headed up the FIA's Expert Advisory Safety Committee, set up in the aftermath of the tragedy of that weekend. And, under his guidance, huge changes were made that has shaped the sport into what it is today.
Immediately, tracks were reworked to add extra safety features at the most dangerous corners. Larger asphalt run-off areas were put in place where possible, giving drivers who go off track more control than grass or a gravel trap ever would.
Barriers have also become much more absorbent. Long gone are the days of hay bales or concrete walls - these days, soft Tecpro barriers help to cushion the blow of an impact. On the cars themselves, HANS devices were introduced in 2003 and were not initially popular, but have proven to greatly reduce head and next movement in a crash.
HANS has saved countless lives in F1 and other motorsport series, as has the Halo which was introduced in 2018 and also proved controversial at first. But there have been dozens of examples of the titanium bar saving lives.
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Romain Grosjean credited it with saving his life in his fiery Bahrain crash in 2020, and the following year it prevented the wheel of Max Verstappen's car from landing on Lewis Hamilton's head at Monza. And Zhou Guanyu was saved from his head hitting the Silverstone track when his car flipped and skidded across the tarmac on the opening lap of the 2022 British Grand Prix.
Motorsport remains very dangerous and F1's record since Imola '94 is not perfect. Jules Bianchi died from injuries suffered at the 2014 Japanese Grand Prix when he crashed into a recovery vehicle. That only one of the 32 F1 world championship fatalities has taken place in the last 30 years is testament to the positive safety changes that have been made since Ratzenberger and Senna lost their lives.
And, for Damon Hill, who was Senna's Williams team-mate that season, it is an important legacy. He told Mirror Sport: "For all his faults, [then FIA president] Max Mosley acted swiftly and decisively to change the whole sport for the better in respect of our approach to safety. Romain Grosjean is living proof that this sport can be dangerous but safer. Nothing will bring back Ayrton and Roland. But maybe they did not die in vain."