Munis crashing

These are prices, not yields. I stole this chart from Business Insider. As an investor, I would be looking for the rare gem in this mess, the munis that are solidly backed by strong local government with a history of conservative spending.

The center is eating huge chunks of debt, and as the periphery governments adjust, a spiral of gaps in debt availability appear.  The spiral occurs as the government channel adapts from one rank to the lower rank, and spirals offer the minimum number of steps between the two ranks.  Each circle around the spiral causes the size of the gap, the Fibonacci number, to jump.