Updated on September 25 at 3:36 p.m. ET

Every day since the story first broke a week ago, the ripples of Volkswagen’s scandal have extended further and further. Initially, the Environmental Protection Agency ordered Volkswagen to recall nearly half a million vehicles after discovering illegal devices intended to cheat emissions testing. Then, Volkswagen announced the number of vehicles affected is closer to 11 million worldwide—and that the company has set side $7.2 billion to fix the problem. Volkswagen’s CEO at the time, Martin Winterkorn, soon resigned.

On Friday, the company’s board named Matthias Mueller, the chief executive of Porsche, as the new CEO. There are reportedly nearly 30 class-action lawsuits pending from car owners in all 50 states, plus 5 provinces in Canada. All these furious drivers bought their cars believing that they were highly fuel-efficient—which appears to not be the case, affecting their resale values significantly.

But how did this whole thing begin? At a small lab in West Virgina, it turns out. In 2012, a group of researchers at West Virginia University won a $50,000 grant from the International Council on Clean Transportation to do performance testing on clean diesel cars. Arvind Thiruvengadam, a research assistant professor in mechanical and aerospace engineering, told NPR this week that the team was merely excited do the research—which involved driving the clean diesel cars outside the lab—and write a journal paper based on the data. They never expected that they would discover one of the biggest frauds in automotive history.

When Thiruvengadam and his colleagues tested Volkswagen’s clean diesel cars, they found discrepancies up to 35 times the expected emissions levels. The researchers suspected cheating, but couldn’t be sure. David Carder, another researcher on the West Virginia University team, told Reuters that the fallout at hand is surprising because this data was made public over a year and a half ago.

The stakes were upped when the Volkswagen cars in question were tested by the California Air Resources Board (CARB) in an investigation starting May of last year, and the CARB and EPA started discussions with Volkswagen on why there were such discrepancies. Volkswagen insisted to EPA officials that the discrepancies were due to a technical issue rather than deliberate cheating. Only when the EPA threatened not to approve Volkswagen’s 2016 clean diesel cars for sale in the U.S. did the company finally fess up.

Volkswagen will survive this scandal (even though its stock has plunged 30 percent, wiping out a quarter of its market value), but now the future of diesel cars are at stake and it’s expected that the consumers who wanted clean diesel cars for their greenness will likely switch to hybrids, while those who care for performance might try to dodge the recall. Either way, Volkswagen will be held responsible for clean diesel’s coming existential crisis.