In 1957, tragedy struck the Mille Miglia, a nearly 1,000-mile Italian road race that was a showcase for the world’s fastest cars and most daring drivers. With only a few miles left in the grueling, 11-hour race, a Ferrari driven by the dashing Spanish racer Alfonso de Portago blew a tire.

The damaged Ferrari spun out of control and flew off the road, instantly killing de Portago and his co-driver Edmund Nelson. Tragically, nine spectators were also killed—five of them children. The Italian public was outraged and demanded justice for the families of the dead. They found a convenient villain in Enzo Ferrari, the controversial genius behind Scuderia Ferrari, the Ferrari racing team.

The Mille Miglia was never raced again, and Enzo Ferrari was put on trial for manslaughter, capping one of the most difficult years of the auto icon’s life.

Enzo Ferrari is famous for his single-minded pursuit of victory. Ferrari began his career in the 1920s as a race car driver for Alfa Romeo. But he found his true calling off the track, first as a manager of racing teams in the 1930s and then as a visionary carmaker in the 1940s. Ferrari’s first love was racing, and he only started selling luxury sports cars to fund his racing ambitions.

By the mid-1950s, Ferrari the company had emerged as a major player in professional racing, both in the single-seat Formula 1 category and in open road races like the Mille Miglia. But 1956 proved to be a year of both triumph and tragedy for Enzo and his company.

In April of 1956, the Ferrari racing team was victorious at the Mille Miglia, winning the first four places. The grand champion was Eugenio Castellotti, one of the brightest young stars on team Ferrari.

Less than two months later, personal tragedy struck Enzo and his wife Laura. Their beloved 24-year-old son, Dino, succumbed to a years-long battle with muscular dystrophy. Enzo was inconsolable and briefly considered quitting Ferrari. When he was finally ready to return to work, Enzo suffered a second painful blow—his star driver Castellotti was killed in a training accident on the Ferrari test track in Modena.

Castellotti’s death came just weeks before the 1957 edition of the Mille Miglia. For the first time in his life, Enzo Ferrari publicly expressed doubts about dedicating his life to such a dangerous sport.

“Something had changed within Enzo and the way he was looking at motor racing,” says Luca Dal Monte, author of the biography Enzo Ferrari: Power, Politics, and the Making of an Automotive Empire.

The night before the start of the 1957 Mille Miglia, Ferrari gave a speech at a big banquet in Brescia. “Maybe it was the deaths of Dino or Castellotti that made him more sensible to the whole issue of dying,” says Dal Monte. “He expressed doubts the night before the race—that what he’s doing is actually bringing death to people.”

Ferrari had every reason to question the ethics of automobile racing. Just two years earlier in 1955, the racing world was rocked by the deadliest crash in its history.

During the 24-hour Le Mans race in France, a Mercedes-Benz traveling 150 miles per hour collided with another car and went flying into the grandstand. The explosion and fiery debris killed 82 spectators, an unthinkable death toll.

The Mille Miglia itself was no stranger to tragedy. In 1938, a gruesome crash occurred outside of Bologna. A speeding sports car driven by two amateurs launched over a tram line and killed 10 spectators, including seven children. Officials cancelled the 1939 Mille Miglia, but the race proved so popular that they reinstated it in 1940.

The very thing that made the Mille Miglia so thrilling is what made all public road races of that era so dangerous. Crowds of spectators, including families with children, lined the route to see the fastest sports cars in the world up close and personal. Drivers pushed their cars to the limit, knowing very well that the smallest mistake could result in disaster.

Stirling Moss, the late British race car driver who won the Mille Miglia in 1955, described the race to CNN in 2012. “Imagine going up a large incline towards a village and going at 185 miles per hour without knowing which way the road goes,” said Moss. “It was the only race that frightened me, actually.”

The man behind the wheel of the tragic Ferrari crash at the 1957 Mille Miglia wasn’t even supposed to be driving that day. Ferrari only invited Alfonso de Portago to race the Mille Miglia after Cesare Perdisa, another talented Ferrari driver, quit automobile racing entirely after the death of Castellotti.

De Portago was an excellent driver, but racing wasn’t his only passion. The son of a Spanish aristocrat father and a wealthy American mother, the “Marquis” de Portago spoke four languages and played a wide array of sports, from jai alai, to swimming, to professional bobsledding.

“De Portago was the quintessential ‘gentleman driver,’” says Dal Monte. “He was a playboy, a man who had everything he wanted from life. He could afford to buy fancy cars and drive fast.”

De Portago and his American friend Edmund Nelson had tried twice before to race the Mille Miglia, but bad luck hounded them at every turn. In their first Mille Miglia, their car caught fire only hours into the race. The second attempt, they crashed into a mile marker within the first few minutes.

For that reason, neither de Portago nor Nelson knew the entire Mille Miglia route firsthand, ratcheting up the danger of the 1957 race. But de Portago, who once flew an airplane under a London bridge on a bet, equated danger with adventure.

“It is the uncertainty of the future that attracts the adventurer most,” de Portago said. “Few professions…have less security and more uncertainty about the future than motor racing. One can be on top one second, but all it requires is a very small error and one is very embarrassingly dead the next.”

At 3:30 pm on May 12, 1957, de Portago and Nelson were 21 miles from the finish line when they entered a straightaway near the Northern Italian village of Cavriana. Thundering down the road at 155 miles per hour, something punctured the left front tire of the Ferrari, possibly one or more reflective lane markers known as occhi di gatto ("cat’s eyes").

De Portago didn’t have a chance to right the speeding vehicle, which slammed into the left curb and flipped wildly into the air. Ironically, it was the spectators standing farthest from the road—a safer distance, presumably—who were killed or seriously injured by the airborne Ferrari.

Nine spectators died in the crash in addition to the drivers de Portago and Nelson. The youngest of the spectators was 6-year-old Valentino Rigon, whose 9-year-old sister Virginia was also killed.

News of de Portago’s crash made it to the finish line in Brescia long after the winners were crowned. Piero Taruffi, driving solo for Ferrari, took first place in the last race of his long career. Overall, Scuderia Ferrari ruled the day, with 12 of the 16 fastest times claimed by their drivers. But within hours, none of those victories mattered.

“When you read the Italian newspapers from that day, nobody talks about Taruffi winning the last race of his career,” says Dal Monte. “All they talk about is the tragedy and the public outcry.”

All future runnings of the Mille Miglia were immediately canceled, as were all other public road races in Italy. As the families grieved their lost loved ones, the Italian press pointed the blame squarely on one man: Enzo Ferrari.

In the Osservatore Romana, the official newspaper of the Vatican, editorial writers compared Ferrari to Saturn, the mythological Titan who ate his own children in order to live. Ferrari was painted as a callous, hyper competitive tyrant who would sacrifice anything to win, including innocent lives.

Dal Monte says that the opposite was true.

“The crash at Mille Miglia was probably the worst thing on a personal level that ever happened to [Enzo],” says Dal Monte. “Death in motor racing was nothing new, sadly, but this time it was different. Not only were they spectators, but five of them were kids.”

Soon Ferrari found himself facing something far worse than bad press or a tormented conscience. He was charged with 11 criminal counts of manslaughter.

At first, the situation looked bleak for Ferrari. An expert panel assembled by the prosecution produced a damning report. It accused Ferrari of recklessly cutting corners by fitting his race cars with tires that weren’t up to the task.

Dal Monte, who wrote a book about Enzo’s manslaughter trial, says the entire history of automaking could have been different if Ferrari was found guilty.

“If Enzo’s found guilty, he goes to jail,” says Dal Monte. “If he goes to jail, his factory shuts down. If his factory shuts down, there’s no Ferrari today. I don’t think it’s an exaggeration to say, if he’d been found guilty, history would have been written a different way. Not only the history of Ferrari, but the history of automobiles and certainly of auto racing.”

More than three years into the trial, Ferrari convinced the judge to convene a new panel composed of actual automotive engineers. In a new report, the engineers blamed the accident on the “cat’s eye” reflectors, not Ferrari’s negligence. He was acquitted of all charges.

Through all four years of the trial, Ferrari didn’t stop working. Only weeks after the Mille Miglia crash, in fact, Scuderia Ferrari was scheduled to race in the next meeting of the 1957 World Sportscar Championship. Ferrari even petitioned the judge in the manslaughter trial to release two undamaged Ferrari race cars that were being held as evidence. The team needed them.

“It shows you that life did not stop with the crash,” says Dal Monte. “Ferrari the man and also the company had to keep racing.”