Motorsport: Claire Williams reflects on Formula 1 icon Ayrton Senna's tragic death

A quarter of a century after Ayrton Senna was killed in a car bearing her family's name, Claire Williams is reliving the tragedy of F1's darkest day.

"About a year later I remember being in a pub," she explains. "I don't know how he knew who I was, but a complete stranger came up to me and said, 'Your dad is a murderer'.

"It hadn't really sunk in about how people might feel about the accident. That's not what happened but I guess some people are ignorant."

Senna was F1's brightest star, a sporting giant, an icon in his native Brazil. But on lap seven of the ill-fated San Marino Grand Prix — a black weekend that had already claimed the life of Austrian Roland Ratzenberger — he ran off the road at 306km/h and hit a concrete wall. He died instantly, aged 34.

While F1 driver Jules Bianchi died nine months after a crash at the 2014 Japanese Grand Prix, Wednesday marked the 25th anniversary of Senna's death in Imola — the last time a driver was killed at a Formula One race.

Sir Frank Williams, the team's extraordinary founder, was cleared of manslaughter charges in 1997. The exact cause of the crash remains inconclusive.

"Frank never spoke to anyone about it," Claire, now the de facto boss of the British F1 team, told Press Association Sport.

"That isn't his personality. He isn't one for therapy, or having long conversations. He internalises and keeps it all in. That is how he has been brought up, but you can see the pain in his eyes every time he thinks about the accident."

Senna was competing in just his third race for Williams, who were then the kings of the Formula One road. Nigel Mansell had galloped to the drivers' title in 1992. Alain Prost won the championship a year later. Williams then landed the driver he had dreamt of signing.

"Ayrton was a god in our house and had been for many years, decades even," says Claire.

"Frank had a love-affair with Ayrton. He got into his heart, got into his mind, and he always wanted to put him in his race car.

"Dad's wish then came true, but it ended in the worst possible way."

Frank Williams remains the team principal of a constructor which has won 16 combined championships. But his title is now largely in name only. The 77-year tetraplegic has been consigned to a wheelchair for more than three decades after a road accident in 1986.

He no longer travels to races, leaving his daughter Claire in charge. Yet on that fateful day in May, she was a 17-year old schoolgirl, preparing for her mock A-Levels.

"I was watching the race in my bedroom," she says. "Dad was obviously away, and mum (Lady Virginia Williams) was watching it downstairs.

"It was just a horrific accident, and it felt as though something suddenly came over the house. It was really odd.

"Quite quickly, my mum came upstairs. I was due to go back to boarding school at 6pm that evening, and mum said you are going now. I knew then that something serious was going on.

"I was put on a train and sent away. My parents preferred to shelter us from it. They did that with dad's accident and they did so with Ayrton's death, too."

Tragically for Williams it marked the second time a driver had died in one of his cars. Piers Courage lost his life in a fireball inferno at Zandvoort, Holland, in 1970.

"It was an excruciating thing to happen to dad again," added Claire. "He went to Ayrton's funeral in Brazil which, from a safety perspective, we were all very worried about because Ayrton was an enormous hero and he died in our car, but Frank wanted to be there.

"We all then went to the memorial service in London. I'll always remember my mother saying to me, 'There will be no crying on this day, this is not your loss'.

"In our film (released in 2017) there is a scene where Frank is at Ayrton's funeral, and I have never seen my dad look like that.

"There is an extraordinary line where he is asked how he felt that day, and he just says, 'Far from well'.

"I think that says it all. I am sure he felt far from well for many, many, many years, and still today he won't talk about him.

"He will talk about what a great man Ayrton was, and what a great driver he was, but nothing to do with the accident."

Despite the tragedy, Williams carried on. David Coulthard took Senna's seat as Damon Hill became the team's lead driver. Hill fell just one point short of beating Michael Schumacher to the championship.

"I am sure there were days when dad may have thought, 'I don't want to go racing, I want to hide under my duvet'," Claire concludes.

"You just want to stop sometimes, and that was the hardest thing. But people in this sport are made of stern stuff, and Ayrton probably wanted us to keep racing."