WASHINGTON (AP) – The Obama administration on Tuesday accused Standard & Poor’s of refusing to warn investors that the housing market was collapsing in 2006 because it would be bad for business.

The civil charges against the credit rating agency were the administration’s most aggressive action to date against those deemed responsible for contributing to the worst financial crisis since the Great Depression. They followed years of criticism that the government had failed to do enough.

The Justice Department accused S&P of knowingly inflating its ratings of risky mortgage investments that helped trigger the crisis. It’s demanding $5 billion in penalties.