The accident that killed Formula 2 driver Anthoine Hubert on Saturday serves a reminder of the unpalatable truth that motor racing can never be safe.

It has, understandably, cast a pall over the Belgian Grand Prix weekend.

As safety has improved over the years, accidents such as this, and their terrible outcomes, have become increasingly rare. But any time a human being straps themself into a projectile and races closely with other cars at speeds of well over 100mph, they are taking a very serious risk.

This day would otherwise have been filled with talk of Ferrari's front-row lock-out, whether they could finally deliver a win this season, and so on, but people who work in Formula 1 know a bad accident when they see one, and the reaction to this one was instantaneous.

World champion Lewis Hamilton was conducting television interviews at the time and was glancing, as F1 drivers do, at the start of the F2 race.

"Aye, aye, aye," he said, as the accident unfolded in all its horrific violence. "Oh wow. Hope that kid's good. Wow. That's terrifying." He rubbed his forehead, his face a mask of concern, and then walked off, not saying another word.

At Red Bull, their new driver Alexander Albon was holding his news conference with the written media, the F2 race on a television screen behind him.

Journalists inhaled in horror at what they seeing. Albon turned around, watched what was happening, and said nothing. Then, after a minute or so, crossed his hands to indicate to his media handler that the session was over.

Immediately, even though there was no confirmation of the seriousness of the accident, the paddock at Spa descended into silence. People's faces set. Work was undertaken with stoicism and silent contemplation. Motor racing is a hard, brutal business, in a number of ways, but the sport also considers itself a family, and it rarely feels closer than at times like this.

These moments confront racing drivers in a very visceral and immediate sense with the dangers of the profession they chose because they love it. The risk they take is an inherent part of that love, however hard that might be for some to comprehend.

Of course they don't want to be injured, or worse, but the very fact they can be adds an extra frisson to an activity that already rewards its participants with feelings that simply cannot be experienced anywhere else.

The combination of balance, bravery, skill, judgement and excitement that comes from controlling a racing car on the very edge of adhesion at high speed, and trying to beat everyone else while doing it, is what makes racing drivers stand out from other people, and make it different from most other sports.

It is also part of the appeal to the people who watch it. They don't want to see people hurt either, but they appreciate what the drivers are doing, what it requires of them, and what is at stake.

Not for nothing did Hemingway say: "There are only three sports: bullfighting, motor racing, and mountaineering; all the rest are merely games."

As Hamilton said: "If a single one of you watching and enjoying this sport think for a second what we do is safe your hugely mistaken. All these drivers put their life on the line when they hit the track and people need to appreciate that in a serious way because it is not appreciated enough. Not from the fans nor some of the people actually working in the sport.

"Anthoine is a hero as far as I'm concerned, for taking the risk he did to chase his dreams. I'm so sad that this has happened. Let's lift him up and remember him."

Hubert is the first man to die as a result of an accident in a race sanctioned by international governing body the FIA since F1 driver Jules Bianchi, who sustained terrible head injuries in a crash during the 2014 Japanese Grand Prix and died the following July.

The last driver killed in a major international motor race was Britain's Justin Wilson - hit on the head by debris during an IndyCar race at Pocono, Pennsylvania in August 2015.

Since then, there have been a number of serious accidents, but no fatalities, which is a testament to the ongoing work around the world to improve safety.

There will be a full investigation into this accident. It will be considered whether the 'halo' head-protection device, which was introduced last year as a direct result of Bianchi's accident did its job as intended. The forces involved will be analysed. Lessons will be learned, and changes made. But in some cases, there is not much to be done. The human body can only take so much, which is why the risk of motorsport can never be entirely eradicated.

Spa-Francorchamps, where this accident happened, is one of the world's greatest, most historic, fastest, most challenging and, yes, most dangerous race tracks. To a man, the drivers look forward to races there more than those at a mere handful of circuits around the world. But they don't do it lightly. They do it in full awareness of the risks they are taking.

On Saturday night, over dinner with friends and colleagues, the 20 F1 drivers will contemplate the loss of a man who some of them knew, some of them had raced against, and of which some were only aware as someone who could very well one day soon be one of them.

On Sunday, they will wake up and drive into Spa, and go about their usual pre-race preparations. They will do it with seriousness, sobriety, and an iron determination to carry on with business as usual.

Then, at 1510 local time on Sunday, they will watch five red lights come on one by one and then go out, and within a few seconds they will be racing nose to tail and perhaps even side-by-side at close to 200mph over the exact spot where less than 24 hours before a colleague paid the ultimate price.

The sport they love brings them incredible highs and, as on Saturday, awful lows. The combination of all that is - whatever one may think of it - what makes it so thrillingly, awfully, terribly, tragically, special.

They are truly not as other men.

Formula 1 bosses Chase Carey and Ross Brawn have committed to staying in their roles to complete the process of overhauling the sport.

F1 is in the middle of discussions over new rules from 2021, including a revamp of the cars and introduction of a budget cap.

Chief executive Carey and managing director motor sports Brawn will stay on at least until the new structure is completed and stabilised, BBC Sport can reveal.

But commercial boss Sean Bratches is tipped to leave F1 at the end of this year.

The commercial structure of the sport will be revamped over the winter and senior sources say that Bratches, the managing director commercial operations, will not stay in his post.

Bratches, a former vice-president of sales and marketing at US television network ESPN, joined F1 with Carey and Brawn when the sport was take over by US group Liberty Media at the start of 2017.

F1 declined to comment on the contractual position of its three senior managers.

The commitment by Carey and Brawn means both are set to stay in post at a minimum through the first part of 2021, to ensure not only that the rules process is completed but that any teething problems that emerge that season will be dealt with by experienced hands rather than newcomers.

It is understood that both Carey and Brawn are determined to finish what they started, have strong relationships with Liberty bosses and are minded to stay as long as is needed.

The move gives the sport stability and may act as a reassurance to shareholders and investors at an uncertain time.

Other than Renault, the teams' contracts do not run beyond the end of next season and talks over the 2021 rules are at a delicate stage.

Brawn and his technical team have been working on a major revamp of the rules that is aimed at closing up the field and making the cars able to race much more closely together.

There are also plans to introduce a series of standard parts which it is hoped, when combined with a budget cap of $175m a year for car operations, will close up the field.

However, the top three teams Mercedes, Ferrari and Red Bull are opposing such sweeping changes.

They feel that introducing so many changes at once could backfire and would prefer to keep the technical rules pretty much unchanged. They are also opposed to many of the standard parts as they feel using them will reduce quality, increase the cars' weight and not significantly reduce costs.

Their argument is that the budget cap is already agreed and that its introduction renders the need for standard parts obsolete.

This has caused a stand-off between Mercedes, Ferrari and Red Bull on one hand and F1, governing body the FIA and the other teams on the other.

There are even suggestions that Ferrari could use its power of veto over the 2021 technical changes if a compromise that they find agreeable cannot be reached.

There is a deadline of 31 October to finalise new sporting and technical rules for 2021, after which a new revenue distribution and governance procedure needs to be agreed.

At the same time, F1's bosses are discussing potential changes to the format of grand prix weekends next year in an attempt to keep the sport relevant to younger audiences.

One idea being broached is at a select number of races next year to replace qualifying with a race, with grid positions set in reverse championship order and the finishing positions defining the grid for the grand prix on Sunday.

This and other proposals will be discussed at the next major meeting of teams and bosses in Geneva next month.

The Formula 2 race at the Belgian Grand Prix has been cancelled following a serious crash.

The race was halted on the second lap following the incident at Radillon bend, involving BWT Arden's Anthoine Hubert and Sauber Junior team's Juan Manuel Correa.

The impact was so severe Correa's feet were exposed as the nose cone was destroyed and he was trapped in the cockpit upside down.

The monocoque from the BWT Arden was separated from the rear of the car.

The incident occurred at Turn Three of the Spa-Francorchamps circuit, which follows the famous Eau Rouge corner at speeds of around 160mph in Formula 2 cars.

More to follow.

Charles Leclerc set a scintillating lap to beat Ferrari team-mate Sebastian Vettel to pole position at the Belgian Grand Prix.

The 21-year-old, still seeking a first career win, was a massive 0.748 seconds clear of his four-time world champion team-mate.

Mercedes' Lewis Hamilton was second quickest after the first runs but was pipped by Vettel on their last laps after the world champion failed to improve.

Mercedes' Valtteri Bottas was fourth ahead of Red Bull's Max Verstappen.

More to follow

Lewis Hamilton had a heavy crash in final practice at the Belgian Grand Prix, raising questions about his participation in qualifying.

The world champion lost control entering the Fagnes chicane, trying to improve a lap time 0.35 seconds down on team-mate Valtteri Bottas.

The car's front-left corner was damaged as Hamilton hit the barriers, head on.

Charles Leclerc led Sebastian Vettel to a Ferrari one-two in the session, 0.497secs ahead of Bottas.

Daniel Ricciardo's Renault was a surprise fourth fastest, just 0.271secs slower than Bottas and ahead of Red Bull's Max Verstappen, who was 1.106secs off the pace.

Ricciardo is one of six drivers with a grid penalty this weekend as a result of using more than the permitted number of engine parts.

Sergio Perez's upgraded Racing Point also impressed, with sixth fastest time.

The concern for Mercedes and Hamilton will be two-fold: can they get the car repaired in time to run in qualifying at 14:00 BST; and whether the gearbox has been damaged, which would mean a five-place grid penalty.

Hamilton lost control when he got a front wheel too far onto the outside kerb on entry to the 130mph chicane.

He almost caught it as he fish-tailed through the asphalt run-off area but ran out of space to stop the impact.

The rear of the car looked undamaged, with the front-left corner taking the brunt of the damage, but it remains to be seen whether the driveshaft took an impact that could affect the gearbox.

Ferrari look strong favourites for pole position, which appears at this stage to be a straight fight between Leclerc and Vettel whether or not Hamilton's car is ready.

It is a golden opportunity for Ferrari, who are yet to win a race this year, and failed to capitalise on their one-lap superiority at the German Grand Prix last month when both cars hit engine trouble in qualifying.

But on Friday the red cars were not as competitive on race pace, struggling with excessive tyre wear, and the race might be a different matter.

'Rethink racing' - that's what the W Series asked us to do.

In six races over a four-month period, the female-only motorsport championship has generated significant interest in a male-dominated industry with the ultimate aim of getting women on the grids of top-level racing.

The series is designed to help women break through the 'glass ceiling' often experienced after junior karting, when drivers embark on the quest for sponsors to fund the next level of a career in motorsport - which can cost millions.

Originally criticised for segregating women from male competition, several of the 20 women who lined up on the W Series grid have been handed a chance they would not ordinarily have had.

Just a week after the series finale, a number of drivers have earned paid seats elsewhere.

Female, gifted and broke

When driver Alice Powell sought sponsorship, the response she often received was: "We're not sure that a woman in motor racing is the right positioning for us."

The first race of the series in Hockenheim, Germany, was Powell's first time behind the wheel in five years because of the struggle for backing.

Before the W Series came along, her dream of being a full-time racing driver appeared to be over and she worked as a labourer for the family firm, renovating properties.

Powell said: "Then W Series came along and changed the game. I had just been unblocking a urinal when I got the call."

Following Powell's second place at Hockenheim, Powell took W Series CEO Catherine Bond Muir to one side. Bond Muir explained: "She hugged me and said 'thank you for making me feel like this again'."

Bond Muir, who has become known for her close relationship with all the drivers in the series, added: "Alice was the first woman in GP3 to get points and then her career stopped and there was nothing for her, and this has given her the opportunity to show the world what a great driver she is."

Two days after Powell won her first W Series race in the season finale at Brands Hatch, it was announced she will drive for Heinricher Racing in IMSA GT3, a top-level sportscar championship, alongside British driver Katherine Legge; racing in W Series certainly helped her cause.

'It's been incredible'

Powell's is not the only success story. W Series champion Jamie Chadwick, who sealed the title at Brands Hatch, is backed by Aston Martin's junior driver programme, and won her class in the Nurburgring 24 hours race. She also signed for the Williams Formula 1 team as a development driver in May.

Chadwick told BBC Sport: "I was relatively unknown coming into this season and now I think the leg up the W Series has given me has been huge... I think as a first year of the series goes, it's been incredible what they've managed to achieve."

Spain's 19-year-old Marta Garcia, who was one of five different drivers to win a W Series race, said she was "relieved" to be on the grid 18 months after being short of money and dropped by Renault's driver academy in Spanish Formula 4 following just one season in the car.

Now, after finishing fourth overall, Garcia plans to invest her £82,500 prize money in the Toyota Racing Series in New Zealand.

Sabre Cook, an American engineer working for Infiniti and Renault in Formula 1, competed in the W Series to become one step closer to racing in the USA's biggest single-seater series, IndyCar. Italian driver Vicky Piria - who finished ninth in the W Series championship - was in touching distance of being an F1 test driver in 2013, aged 18, until it fell through.

What's holding women back in racing?

When W Series chairman Sean Wadsworth's children had a go-kart race, he told his 11-year-old daughter "you could be a racing driver". She replied: "There's no point." Wadsworth asked why and she responded: "Because women don't do that."

The W Series was Bond Muir's idea, born over drinks with some friends. After doing some research and finding that women can race equally in motorsport, Bond Muir initially felt a women-only category was "a completely dreadful idea because there's no need for it".

She told BBC Sport: "And then I did more research and found that in the previous eight years the number of women competing in single-seater series across the world was actually diminishing year on year. I thought 'actually, there does need to be this platform'."

In motorsport, it's no secret that drivers need huge sums of money to make it - around £7m to get from junior karting to Formula 1.

Chadwick added: "Financial backing is the biggest hurdle and it's the same for everyone. If you look at all the drivers that have made it into F1 now, they have all come with significant backing whether that's personal or through sponsors or a team. None of them have paved the way by scraping the barrel.

"It's tough, it's the way the sport is, but hopefully this has put me in a position to make that happen."

Wadsworth highlighted the success of the US women's football team, saying: "Nike started investing in them 10-15 years ago and that allowed them to become professional sportswomen.

"The big difference between what we have here and what Lewis [Hamilton] can do, or the rich kids in Formula 2 [the feeder series into F1], is Alice Powell has to fit toilets with her dad at the weekend because she's not a professional athlete."

As well as providing 20 women with the opportunity to race, it has given them media exposure on a global level. The races have been broadcast to more than 300 million people in more than 70 countries.

Wadsworth added: "Fabienne Wohlwend has just given up her job, and I think there's three of four of them going to be resigning from their jobs because they can now be professional athletes."

What happens next?

Many elements of the series have been distinctive and refreshing and it's all in the detail; from giving the top 10 drivers a share of the £1.2m prize pot to reinvest in racing, to the complimentary chocolates in the hospitality area which include helmet designs of past female F1 drivers.

"W Series has changed many perceptions since its launch, including my own," said motorsport journalist Luke Smith. "I was initially doubtful of the series' necessity, but it has quickly proved itself to be a massively positive force for women in motorsport.

"It is helping to shine a spotlight on female racers, as well as opening up more doors for them. Beyond that, its wider message looks set to help inspire the next generation of women in motorsport both on and off the race track."

The W Series may have been set up to help raise female participation, but it has also created a platform to solve one of motorsport's big challenges - the cost of competing, at least for women.

There are valuable superlicence points on offer next year for those with aspirations to compete at the top level. It is 43 years since a woman started an F1 race and the W Series has made the idea of a female driver racing at the pinnacle of motorsport more realistic.