New York Fed President William Dudley did not comment on U.S. interest rates in a presentation of research on the effects of the storm that struck on Sept. 20. It was the worst natural disaster in 90 years and the largest government bankruptcy in U.S. history.

The Federal Reserve Bank of New York, whose district includes the Caribbean island, said Maria wiped out about 4 percent of its jobs, the fifth-worst among U.S. disaster regions in recent decades. Dudley said it will likely take “many more months” to restore electricity and critical infrastructure to Puerto Rico, adding it was unclear how many of the tens of thousands of residents who fled will eventually return.

Given the already outdated and inefficient power plants, he said, “now is a perfect opportunity for Puerto Rico to essentially start from scratch and build a resilient power generation and distribution network.”

Hurricane Maria killed dozens and left Puerto Rico’s 3.4 million U.S. citizens without power, along with reducing access to clean water and other essentials. The U.S. agency responsible for disaster response has been criticized for hiring contractors that failed to deliver relief to the island, and last month said it would continue to provide water, meals and other basic needs after earlier reports that it was going to halt aid.

Some 179,000 net people left Puerto Rico after the hurricane, with likely 20,000 to 30,000 of those tourists, the New York Fed found. While it was hard to predict how many might return, New York Fed research analyst Jason Bram told reporters that relatively higher home ownership and lower mortgage debt “creates a little more links to the island.”

Assessing overnight satellite images of light on the island, seen as a creative proxy for economic activity, the New York Fed found the island was 76 percent as bright in January as it was before the hurricane hit in August. In October, given the mass power outage, Puerto Rico appeared to have only a fraction of its normal night light.

Dudley, who is set to leave his post by mid-year, said however that the island’s labor market appears to have stabilized thanks to a return of hospitality jobs and the emergence of construction. “These job gains are expected to continue for some time to come,” he told reporters at the New York Fed.

(Notes mass power outage in line about satellite images.)