Eventually it was students and faculty at a West Virginia university who tripped them up. They discovered that Volkswagens in road use were emitting much more nitrogen oxide than specifications called for, and contacted regulators.

Many automobile recalls seem to result from engineering faults that occurred because components were not thoroughly designed or tested. In this case, however, Volkswagen intentionally put cars on the road that exceeded pollution maximums and were harmful to the environment, all the while touting how clean their diesels were.

Volkswagen’s CEO is out, along with a few subordinates, and its stock price has dropped considerably. The merits of diesel motors in general has also been called into question.

Volkswagen can expect to be heavily fined, which is a given, but as the investigation into who knew what unfolds it is not impossible to consider criminal penalties for those involved. Purposely polluting while claiming otherwise is not what is expected at one of the world’s largest corporations.