The head of Puerto Rico’s embattled power authority stepped down Friday, nearly two months after Hurricane Maria left much of the island without electricity.

Ricardo Ramos, executive director of the Puerto Rico Electric Power Authority, known as PREPA, submitted his resignation to the bankrupt utility’s board. It’s effective Friday, according to PREPA.

The resignation comes days after Puerto Rico’s governor celebrated that power generation had reached 50% capacity, only to see an outage leave parts of San Juan without power for hours.

PREPA’s statement did not say why Ramos was stepping down. It said he would offer additional information later Friday on Twitter.

Gov. Ricardo Rosselló posted articles on Twitter about an event he attended in which he told reporters that Ramos’ tenure at PREPA had become “unsustainable.”

PREPA faced widespread criticism for signing a $300 million contract to restore power with Whitefish Energy, a small Montana-based firm with only two employees at the time of the contract.

The state-owned utility company agreed to cancel the deal shortly afterward amid public outcry.

“I chose to contract with Whitefish because my priority was securing the immediate assistance that we needed to begin restoring power as quickly as possible to our most critical customers,” Ramos said in prepared testimony at a Senate hearing this week.

The island’s emergency management director resigned one week ago as Puerto Rico slowly recovers from the devastating hurricane.

In announcing the resignation of Abner Gómez, Rosselló praised the work of his emergency management chief following Hurricanes Irma and Maria, which both hit in September.

The emergency management director came under fire after the island’s El Nuevo Dia newspaper reported he took a two-week vacation shortly after Maria made landfall on September 20.