Here's what he said a couple of months back:
Sanders Statement on Puerto Rican Debt Crisis
APRIL 1, 2016
NEW YORK U.S. Sen. Bernie Sanders issued the following statement today calling on Congress and the Obama administration to put the people of Puerto Rico over the interests of financial firms in any legislation to address the Puerto Rican debt crisis:
There is a humanitarian crisis in Puerto Rico that Congress and the administration must address as soon as possible. But let me be clear: Establishing an unelected oversight board that would be given the power to inflict even more economic pain on the 3.5 million American citizens in Puerto Rico would be a move in exactly the wrong direction. It must be defeated.
The economic situation in Puerto Rico will not be improved by closing more schools, firing more teachers, laying-off more workers, slashing pensions and suspending the minimum wage. Instead, Puerto Rico must be given the time it needs to restructure its debt and grow its economy in a fair way.
Congress must act immediately to give Puerto Rico the same authority granted to every municipality in this country to restructure its debt under the supervision of a bankruptcy court.
We must not give in to the demands of vulture funds and Wall Street investment banks who are demanding a 100 percent return on their investments. Instead, these wealthy investors must take a significant haircut. The people in Puerto Rico should not be asked to suffer even more, so that a handful of wealthy investors can become even wealthier. Moreover, if any of Puerto Ricos debt was incurred in violation of its Constitution it must be immediately set aside.
SOURCE:
https://berniesanders.com/press-release/sanders-statement-puerto-rican-debt-crisis/
Here's what he's proposing to do now:
Unlike a bipartisan House of Representatives bill that would establish a federal oversight board to renegotiate the massive debt with investors, Sanders' bill would create a "Reconstruction Finance Corporation of Puerto Rico" that would protect public pensioners from cutbacks and "concentrate losses among vulture funds," according to a summary.
"It is morally reprehensible that Wall Street vulture funds are demanding that Puerto Rico fire even more teachers, close more schools, cut pensions and slash the minimum wage so that they can reap huge profits off the misery of the people of Puerto Rico," Sanders said in a statement.
http://www.reuters.com/article/us-puertorico-debt-sanders-idUSKCN0YO2IR
Vulture Funds are a speciality of Goldman Sachs and its enablers in Washington.