Bloomberg said a U.S. government default, just weeks away if Congress fails to raise the debt ceiling as it now threatens to do, will be an economic calamity like none the world has ever seen.

Bloomberg noted that the $12 trillion of outstanding government debt is 23 times the $517 billion Lehman owed when it filed for bankruptcy five years ago.

Bloomberg said that failure by the world’s largest borrower to pay its debt will devastate stock markets from Brazil to Zurich, halt a $5 trillion lending mechanism for investors who rely on Treasuries, blow up borrowing costs for billions of people and companies, ravage the dollar and throw the U.S. and world economies into a recession that probably would become a depression.

To read the Bloomberg story click here.