Loosely speaking, what is meant by a “financial crisis” is that someone borrows money from someone else and can’t pay it back, and it is socially or politically unacceptable that the people who loaned the money not get their money back. That last part is crucial: If someone borrows money and can’t pay it back, and the lender loses money and no one else cares, then that’s just capitalism, not a crisis.
Puerto Rico’s Slide
So part of the trouble in Puerto Rico—which borrowed a lot of money and can’t pay it back—is figuring out how sympathetic the lenders are. The hedge funds telling Puerto Rico to close schools to pay them back: not hugely sympathetic. But the individual retirees, in Puerto Rico and elsewhere, who bought Puerto Rican municipal bonds because they were tax-free and supposedly safe, might be more appealing.
The original source is more explicit:
Puerto Rico’s Slide