Surely Volkswagen (VLKAY) feared the competition. Maybe it worried about regulators. But chances are it didn’t give a fig about the little lab at West Virginia University testing diesel cars on American roads. It should have: It was this scrappy, five-man team of mechanical engineers that first caught on to the German giant’s emissions-cheating ways, kicking off the biggest business scandal of the year (and possibly the decade). VW, the world’s eighth-largest company in 2014, has lost 34% of its market value since the scandal broke in mid-September.

This article is part of Fortune’s Best in Business 2015 package of highlights and lowlights of the year in business, politics and the economy by the writers and editors of Fortune. To see the entire package, click here.

For more on the Volkswagen scandal, watch this Fortune video: