The case of Enron, which took down along with it the audit firm Arthur Andersen, comes to mind in this context. The sudden collapse of Enron, an energy trading and distributing company, ranked seventh in the Fortune 500, raised a number of questions about the accounting and auditing practices followed by the company.
For those who have an interest, I can recommend the excellent book "The Black Swan" by Nassim Taleb, which I reviewed for the Central Bank’s Economic Review, available on the Central Bank of Barbados website.