The deaths of Ayrton Senna and Roland Ratzenberger at Imola 20 years ago this week shook Formula 1 to its core. But their legacy is of vastly improved safety, not just in grand prix racing but all of motorsport.
Senna's death, live on TV in front of around 200 million people, ensured there was the will for drastic changes. This led to a revolution in motorsport safety that means there are drivers and trackside workers still with us today who otherwise would have been lost.
THE INITIAL REACTION