Two weeks after Hurricane Maria devastated islands in the Caribbean, Puerto Rico and the U.S. Virgin Islands are still struggling to bounce back, pushing the islands to the brink of a humanitarian crisis.

An estimated 60,000 roofs were ripped from structures in Puerto Rico, leaving many people without safe shelters, according to the American Red Cross.

Damaged bridges and impassible roads have thwarted relief efforts in Puerto Rico, making it all the more challenging for impacted people to receive much-needed aid.

“It’s been difficult to get around Puerto Rico and the U.S. Virgin Islands,” said Jenelle Eli, director of international communications for the Red Cross.

“Our [more than 600] volunteers have been working around the clock to try to deliver food and water, along with other government partners and non-profit organizations,” Eli said.

In Puerto Rico, ensuring accessibility to roads and emergency power for life-sustaining activities is a high priority, according to the Federal Emergency Management Agency (FEMA).

Worried individuals have struggled to reach family members in Puerto Rico and the U.S. Virgin Islands; FEMA reported that operational cell service in St. Thomas is at more than 48 percent and 21 percent in St. Croix.

Some support from organizations including the Red Cross has helped to ease that burden.

“We have these mobile satellites and we’re bringing them along some of our aid routes in Puerto Rico,” Eli said.

“It’s allowing people to charge their cell phones [and to] access Wi-Fi so they can reconnect with their family members, some of whom they haven’t spoken to in maybe two weeks,” she added.

More than half of people in Puerto Rico have access to drinkable water as efforts continue to restore quality. Forty-five percent of customers are able to drink water safely, following testing by the Environmental Protection Agency (EPA).

However, there have been reports that a cholera outbreak is imminent as a result of the lack of clean water.

Factors including the presence of the V. cholera bacterium, weakened infrastructure and limited drinking water access can all contribute to outbreaks of the illness, according to the Baylor College of Medicine.

Other diseases, including E. coli, typhoid fever and dysentery are additional disastrous risks, and dwindling medical supplies mean that typical treatments would not be readily available.

Although power has been restored to at least 59 Puerto Rican hospitals, the lack of fuel supply to the island also poses a potentially deadly risk for people with kidney disease, who need to receive dialysis about three times per week to survive.

Roughly 5,000 people in Puerto Rico face this threat, according to Mike Spigler, vice president of patient services at the American Kidney Fund.

Some dialysis centers have been short on power and fuel to operate, The Hill reported, and many patients don’t have fuel to get to the centers.

Puerto Rico’s secretary of public security, Hector Pesquera, said in an interview that the current death toll in Puerto Rico has not been updated in nearly a week.

While the official government death toll stands at 16, Pesquera acknowledged that many additional victims may have died due to lack of support services in 70 percent of the island’s hospitals, which were forced to close during Maria’s impact.

Organizations like the Red Cross continue to provide those impacted by the storm with essential aid including drinking water and thousands of meals and snacks.

The Red Cross, which has a permanent presence in Puerto Rico, has also provided mental health services, Eli said.

Despite the continued crisis, the recovery process in Puerto Rico and the U.S. Virgin Island is making progress. More than 65 percent of both grocery stores and gas stations are open in Puerto Rico, and 10 airports on the island have resumed operations, according to FEMA.

St. Croix and St. Thomas have also reported adequate fuel supply for power generation and response efforts.

“Recovery is a marathon, not a sprint, so it will certainly take time, not just to assess the needs and reach the people in need, but to make sure that people are able to rebuild back in a way that makes them safer [against] future disasters,” Eli said.

President Donald Trump is scheduled on Tuesday to visit Puerto Rico for the first time since Maria’s impact on Sept. 20.