With all eyes on Greece it would seem another crisis relating to unpayable debt is brewing in the Caribbean. The governor of Puerto Rico, Alejandro García Padilla, has warned that the island is unable to pay its debts of $72 billion.

Puerto Rico has managed to rack up an astounding level of debt relative to the size of its economy. Moody's estimates the small U.S. territory to have bond debts fifteen times greater than the median bond debt of the 50 U.S. states.

Padilla has warned that by 2025 the island could have bond debt of up to $40,000 for every man, woman and child – in a territory with high unemployment and where the average annual wage is less than $20,000.

The debt was amassed by offering too-good-to-be-true terms to U.S. investors wishing to avoid paying high taxes at home. Interest paid on Puerto Rico's bonds are tax exempt in the U.S.

A complicated set of arrangements lulled investors into a false sense of security with regards to Puerto Rican bonds. For a start, the constitution "contains an unusual clause that requires general-obligation bonds to be paid ahead of virtually any other government expense," according to the New York Times.The government then promised specific revenue streams to different groups of bondholders.

The 2008 crisis hurt the economy badly and the government continued to promise more and more revenue streams in order to issue more and more bonds, the funds from which were used to finance current expenditure. Now there is simply not enough cash to finance debt and public services.

The governor did not specifically say that debts would be restructured. He did, however, say that he was "guaranteeing our citizens essential services and our pensioners a just income."

Now, bondholders are at risk as are the funds which hold Puerto Rican bonds and, more importantly, those who insure them in the derivatives market.