While Volkswagen could face up to $18 billion in fines for an emissions cheating scandal its stock was devalued $16.9 billion today.

It was the largest one-day slide since November 2009, and comes at a time the German automaker is facing challenges in other arena. The shares declined by 13 percent to 140.95 euros by 0207 EDT.

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Among issues are the company’s former chairman Ferdinand Piech had resigned five months ago in a power struggle with present CEO Martin Winterkorn over strategy and the company had been poised to shake off doubts about its leadership.

Then Friday a strongly worded accusation by the EPA named the company a cheater by intentionally installing a device to trick emissions inspectors into passing its diesel cars.

The company has acknowledged the allegation, and its CEO has apologized saying it has no tolerance for law breaking.

Volkswagen is also facing falling sales in China, other operational issues, and its VW brand had already been struggling with profitability.

“This disaster is beyond all expectations,” said Ferdinand Dudenhoeffer, head of the Center of Automotive Research at the University of Duisburg-Essen.

Business Insider.