For a decade, French former childcare worker Sophie Rollet carried out her own, lonely investigation to make US auto equipment group Goodyear accountable for the death of her husband, Jean-Paul, in a collision linked to the company's tyres.
The 50-year-old mother of three's work finally paid off this past week, as authorities raided Goodyear sites in Europe, including its Brussels headquarters, as part of a probe into involuntary manslaughter.
In her stone house in Geney, a village in eastern France, Rollet sat every day for years in front of a computer that she used to meticulously track clues, data and articles on all road accidents linked to explosions of a specific model of Goodyear tyres.
Jean-Paul died on July 25, 2014, on highway A36 in the eastern Doubs department at the age of 53.
He was on his way home after completing a delivery when his tanker truck was hit by a semi-trailer that was rolling in reverse after its front left tyre burst. Both drivers died instantly.
Rollet's investigation led her to link the tyre's model, Goodyear Marathon LHS II, to many other accidents in France and Europe.
"Ten years of working against the grain, almost entirely alone... I often asked myself, 'which door haven't I knocked on?'" the calm but determined woman said.
After her husband's case was initially closed, Rollet filed a complaint in 2016 for involuntary manslaughter and handed her personal findings to prosecutors in the city of Besancon.
An expert was handed the case. His analysis of the tyre concluded that the blowout that caused the semi-trailer to lose control was due to a manufacturing defect, not an external factor.
"This expertise fundamentally changed the case as it validated Mrs. Rollet's findings," recalled Besancon prosecutor Etienne Manteaux.
Manteaux likened Rollet to Erin Brockovich, the US activist whose legal battle against a major American corporation was immortalised in a movie starring Julia Roberts.
"Her determination was central to making the investigations move forward," he said, hailing her "courage and tenacity".
Prosecutors in Besancon have since added two other cases to their probe involving similar accidents that killed two people.
Media coverage and a documentary into her legal crusade prompted another whistleblower, who remains anonymous, to hand the authorities a USB key containing internal documents suggesting that Goodyear was aware of defects of certain tyre models and tried to cover it up.
On Tuesday, authorities searched Goodyear's European office in Brussels, a site in France and the factory that produces the tyres in question in Luxembourg.
Goodyear said it was "cooperating fully" with the authorities.
"For me it's a sort of achievement, a relief," Rollet said, feeling that she had "finally" passed the baton in the case.
But the trained firefighter said she also felt frustrated.
"Justice won't be perfect," Rollet said. "We will never be able to identify all the victims 10 years later."
Rollet, however, said it was "time for me to put some distance between me and this case, which has been relatively demanding".
"You can't confuse determination with obstinacy."
Rollet is now training to become an accountant but she still occasionally goes to schools and businesses to talk about road safety.
"I did my part," she said. "I just turned 50 and today I want to think a little bit about myself."
