The track had been gone from Formula One for a year. Dutch organisers had skipped 1972 to rebuild the circuit: new asphalt, new barriers, a new race control tower. Returning to the calendar in 1973, Zandvoort was supposed to be safer than before. It was the tenth round of fifteen in that year's championship. Jackie Stewart, driving for Tyrrell and chasing his third world title, came into the race tied on win count with the late Jim Clark, who had set a record of twenty-five career victories before his own death at Hockenheim in 1968. A win at Zandvoort would make Stewart, at thirty-four, the most successful Formula One driver of all time. He would get it. James Hunt, his friend and a future world champion, would take third place for his first podium finish - the beginning of a career that would carry him to a title three years later.

Williamson had qualified eighteenth in a privately-entered March 731 run by Tom Wheatcroft. He had been on the F1 grid only once before, at Silverstone, where a multi-car accident had ended his race almost immediately. Zandvoort was his real debut. On lap eight, through the high-speed esses near the Tunnel Oost right-hander, something failed - most likely a tyre. The car pitched into the barriers at speed, was catapulted nearly 300 yards across the track, and came to rest upside down against the barriers on the far side. The fuel tank had been gashed during the slide. The car was on fire when it stopped. Williamson was uninjured by the impact but pinned. He could speak. He was asking to be pulled out.

David Purley had watched the crash from his own car. He pulled over on the opposite side of the track and ran across it - cars still passing at racing speed - to reach Williamson. He tried to flip the car back over. He could not do it alone. He grabbed a single fire extinguisher; it was not enough. He waved at drivers to stop. Race control thought the burning car was Purley's own, and that the man waving the marshal flag had walked away unhurt. Drivers, seeing one upright man at the scene, assumed the same. The race continued under local yellow flags rather than being stopped. Some spectators climbed the safety fences to help; they too were driven back by the heat. Purley kept trying. Footage of those minutes is unbearable to watch. By the time the fire truck arrived - having taken the long way around the circuit at racing pace - Roger Williamson was dead. A blanket was thrown over the wreck. The race continued. Jackie Stewart won.

Purley was awarded the George Medal, Britain's second-highest civilian award for bravery, for what he had tried to do. He had done everything one person could do, and it had not been enough, and that was a failure of the sport, not of him. Williamson's ashes were scattered at an undisclosed location, kept private by his family and his team owner. The 1973 season would not be done with grief: Francois Cevert, who took second place on the podium at Zandvoort that day, would be killed in qualifying for the United States Grand Prix at Watkins Glen in October. Stewart, who had planned to retire at the end of the season, withdrew from his final race after Cevert's death. The footage of Williamson burning while a race went on around him became one of the formative documents of modern motorsport safety. Marshal training changed. Fire-retardant gear became standard. Race control protocols were rewritten so that a single ambiguous wave could no longer be misread for eight fatal minutes. The sport that watched Roger Williamson die was not the sport that came after him.

Officially, Stewart's twenty-sixth Grand Prix victory was the headline of 29 July 1973 - the day a Scotsman finally surpassed Jim Clark's record. Coincidentally, it was also the hundredth Grand Prix won by a British driver. The starting grid that day was set out in 3-2-3-2-3 formation, the last time Formula One would line up in more than two columns. Hunt's first podium opened a door that would lead him to a 1976 world championship in one of the sport's most storied seasons. Stewart would clinch his third title weeks later and retire, the most successful Formula One driver in history. He has spent the half-century since campaigning for the safety reforms that came too late for Roger Williamson, and never let the sport forget.