(CNN) -- A British professor who was key to improving Formula One's safety has died at the age of 84.
Sid Watkins, who was a close friend of the late Ayrton Senna, was involved in F1 for a quarter of a century, helping to save the lives of drivers such as Rubens Barrichello and Mika Hakkinen following high-speed crashes.
"This is a truly sad day for the FIA family and the entire motor sport community," FIA president Jean Todt said in a statement released by motorsport's global governing body.
"Sid was loved and respected in equal measure by all those who knew and worked with him. We will always be grateful for the safety legacy that he has left our sport."
F1 supremo Bernie Ecclestone brought Watkins into the sport in 1978 during an era when fatalities in the sport were all too frequent.
"Watkins worked tirelessly to improve that situation, helping bring universal standards to circuit medical centres, teams and cars, and making the presence of a medical helicopter mandatory at F1 events," said the sport's official website.
The Liverpool-born former neurologist is perhaps best known for his friendship with legendary Brazilian driver Senna.
Watkins tended to the three-time drivers' champion following his fatal crash at Imola in 1994.
Senna's nephew Bruno, currently a driver for Williams, used his Twitter account to say: "RIP Prof. Sid Watkins. Sad news for us who stay behind."
During that fateful Imola weekend, after seeing Aryton Senna's reaction to the death of another driver -- Austrian Roland Ratzenberger -- as well another serious accident involving the Brazilian's compatriot Barrichello, Watkins had advised Senna to quit the sport, asking him: "What else do you need to do?
"You've been world champion three times. You are obviously the quickest driver. Give it up and let's go fishing".
Former Ferrari driver Barrichello also expressed his sadness and gratitude, saying: "It was Sid Watkins that saved my life in Imola 94. Great guy to be with, always happy...thanks for everything you have done for us drivers. RIP."
McLaren's British pairing of Lewis Hamilton and Jenson Button also took to Twitter to express their condolences.
"It's a sad day, with the loss of professor Sid Watkins," said 2008 champion Hamilton. "Without his incredible contribution to the sport, our lives as drivers would be a risk. My condolences go out to his family."
Button, a title winner in 2009, said: "Rest in Peace Sid Watkins...Motorsport wouldn't be what it is today without you. Thank you for all you've done, we as drivers are so grateful."
In recognition of his work Watkins, who was affectionally known as "the Prof", was made the first president of the FIA institute after he left F1 in 2005.
He retained an honorary presidential role following his retirement last year.
"Sid was a true gentleman of our sport and always a pleasure to work with," said current FIA Institute president Gerard Saillant.
"He will be sorely missed by everyone who knew him, from doctors and drivers to officials and fans. Sid's influence will live on for many years to come."