Puerto Rico is in the early stages of its emergency response Thursday after Category 5 Hurricane Irma swept over the entire side of the island Wednesday evening and left 1.1 million without power for what could be months.

"The hurricane has passed. Now we are in an emergency situation, making sure that everyone is safe. We are assessing the levels of damage, and the need for recovery and assistance," Puerto Rican Gov. Ricardo Rossello told the Washington Examiner in a statement Thursday.

Hurricane Irma's 185-mph winds knocked out power for 70 percent of the Puerto Rico Electric Power Authority's customers. PREPA supplies power to 90 percent of the island, but has not shared how many people reside in each residence so it's unclear the portion of the island's 3.4 million total residents are without electricity.

Only 42 percent of the island's hospitals are operational through electric generators, the Puerto Rico Department of Health reported.

Approximately 221,000 customers of Puerto Rico Aqueducts and Sewers Authority do not have service because of electric power incidents.

PREPA warned earlier this week the power blackouts in certain areas will be devastating.

"We are preparing for the worst case and begging for the best case," PREPA executive director Ricardo Ramos said. "[W]e are talking about that there will certainly be blackouts and that there will certainly be areas that will spend three, four months without electricity. But our staff will be giving 100 percent."

Puerto Rico Police stated 6,298 people and 501 pets are in shelters.

Rossello rode the hurricane out at La Fortaleza, the governor's residence on the coast of Old San Juan, where 30-foot waves were reported just miles away.

Rossello's staff said he has spoken with President Trump, Vice President Mike Pence, White House chief of staff John Kelly and Health and Human Services Secretary Tom Price throughout the hurricane.

The governor warned of looming danger from the storm as heavy rains continue to pound the 100-mile-wide island, which is situated in the Atlantic Ocean between the Dominican Republic and both Virgin Islands.

The storm is expected to drop up to a foot of rain in the mountainous region of the island and eight inches by the Rio Grande Manati on Thursday, according to the National Weather Service.

Puerto Rico State Agency for Emergency and Disaster Management Director Abner Gomez said the most affected localities are Utuado, Fajardo, and Culebra.

Trump approved the island's pre-hurricane request to sign an emergency declaration.