Bank debt (the worst kind, and the kind that GCA had) is due on demand. It doesn’t have to come from a bank. It can also take the form of commercial paper, which is loaned from one company to another for short periods of time. The important thing is that it’s due very soon, and sometimes even “due on call.” That means that the lender can ask for his money back at the first sign of trouble. If the borrower can’t pay back the money, it’s off to Chapter 11. Creditors strip the company, and there’s nothing left for the shareholders after they get through with it.