The head of Puerto Rico’s emergency response agency resigned Friday after the governor's office had said he was on a two-week vacation due to exhaustion.

Puerto Rico Gov. Ricardo Rossello extended his "gratitude" to Abner Gomez for his "availability and work over the past months at the helm of these important agencies," according to a statement. “I wish him the greatest of success in his future endeavors."

Gomez was the director of the Puerto Rico Emergency Management Agency in the wake of Hurricane Maria, which has left most of the island without electricity for a month.

Rosello's office had described Gomez as "exhausted" in earlier statements.

The resignation comes as Congress starts the second round of oversight hearings on the hurricane response.

Sens. Lisa Murkowski and Maria Cantwell, the GOP chairwoman and top Democrat, respectively, on the Energy and Natural Resources Committee, will hold a hearing Tuesday.

Murkowski led a congressional delegation to Puerto Rico and the U.S. Virgin Islands to see the challenges for herself. Energy Department officials joined the delegation Thursday.

The House Energy and Commerce Committee also will hold a hearing on the hurricanes' environmental impact next week.

The committees' activities follow a first round of oversight hearings in both the House and Senate on the federal government’s hurricane response.