Experts fear a major health crisis will unfold in Puerto Rico as the island remains without electricity and clean water.

Nearly two weeks after Hurricane Maria hit Puerto Rico, residents and medical professionals are still scrambling to get aid and help for people on the island.

San Jorge Children’s Hospital officials said on Friday they were still treating dozens of patients by using a diesel generator.

While they were finally reconnected to the electrical grid Friday night, the power failed again for nine hours on Saturday.

“The system is fragile and they are trying to stabilize the system,” said San Jorge Children’s Hospital administrator Domingo Cruz Vivaldi.

The hospital was able to switch back to the generator again when the power went out, but Vivaldi said other hospitals weren’t so lucky.

“The San Francisco hospital [in San Juan], they had power generator failure and they had to transfer 40 patients out of the hospital,” he told Healthline.

The power outages at hospitals are just one sign of the continuing hazards facing 3.4 million Americans in the U.S. territory of Puerto Rico as they recover from the effects of the Category 4 hurricane.

The island has 69 hospitals. But as of Monday, just one of those facilities has been declared to be fully operational, according to the Federal Emergency Management Agency (FEMA).

However, nine have had power restored, and 59 are “operational to care for current patients or receiving patients.”

Another problem is dirty water.

Just 45 percent of Puerto Rico residents have access to clean drinking water and only nine wastewater treatment plants are working, according to FEMA.

Vivaldi said at his hospital they’re starting to see the effects of a lack of clean water and food.

“People are not drinking potable water. We are seeing a lot of gastroenteritis,” he said.

Additionally, Vivaldi said they’ve seen children come in with food poisoning because, “people are selling food that was damaged. They are reopening [stores] and selling food that is damaged.”

Currently, the hospital is treating around 80 people. But Vivaldi said he thinks as the roads are cleared, they’ll start to see an influx of people with injuries related to the storm.

With pools of water collecting, he said that they might also see more cases of the mosquito-borne dengue virus.

Dr. William Schaffner, an infectious disease expert at Vanderbilt University Medical Center, said without clean water or wastewater facilities, residents in Puerto Rico are at risk for waterborne diseases.

“My concern would be first of all dehydration, and second of all water-related illnesses,” Schaffner told Healthline.

With contaminated water, “you can get a variety of diarrheal illness. The first one we think about is norovirus,” he added.

Schaffner also pointed out that if there’s a scarcity of food, people may be tempted to eat spoiled food that could make them sick.

Additionally, he said people in isolated areas could be at risk if they don’t get access to medical supplies or care.

He said people with diabetes, heart conditions, or other chronic illness could be at serious risk if they run out of medication and can’t get to a hospital.

“Then, of course, births occur, and if there isn’t gasoline to get to a place where there’s a birth attendant, I think we’re going to run into some difficulties,” he said.

At a press conference on Friday, San Juan Mayor Carmen Yulin Cruz made headlines when she said that the situation in Puerto Rico was dire.

“I am done being polite. I am done being politically correct. I am mad as hell because my people’s lives are at stake,” she said on Friday. “We are but one nation. We may be small, but we are huge in dignity and in our zealous for life. So I am asking the members of the press to send a mayday call all over the world. We are dying here.”

President Donald Trump criticized Cruz on Twitter after her press conference, accusing her of poor leadership.

However, federal officials in the country have stressed how serious the situation is and the need to reach people who are without access to food and clean water quickly.

Army Lt. Gen. Jeffrey S. Buchanan, the joint force land component commander on the island and the Department of Defense Liaison to FEMA, told PBS NewsHour on Saturday the situation was dire for many.

“This is the worst I’ve ever seen,” he said of the damage caused by the storm.

“We’re having the biggest problems in the interior of the island and it’s because of roads,” Buchanan told PBS NewsHour.

“The roads are not clear on the outside of the island and we’re slowly working our way in, but we obviously need to get all the roads clear so we can get supplies to people who desperately need them,” he said.

FEMA had sent at least 800 personnel to both Puerto Rico and the U.S. Virgin Islands to assist with recovery. In total, more than 12,600 federal personnel are on the ground.

The Red Cross told Healthline on Monday that they had 680 members in Puerto Rico and the U.S. Virgin Islands.