Ramon Espinosa / AP

Puerto Rico still doesn’t know how many people died from Hurricane Maria. The official death toll of people drowned in floods, killed by landslides, caught in collapsed houses, or who perished from environmental or health problems in the immediate aftermath of the storm seven months ago sits at 64. By just about all accounts, that is an undercount by at least an order of magnitude. A New York Times review of daily mortality rates found just over 1,000 more people died during and after the storm than expected. Additional analyses suggest similar figures. Governor Ricardo Rosselló is expected to release a full review of the island’s death toll next month.

One difficulty in making these grisly calculations is that Puerto Ricans are still dying from Hurricane Maria. The storm erased the island’s power grid and crushed critical health-care infrastructure, and then the tepid disaster-recovery response allowed infectious disease and mental-health issues to fester for months. There are still plenty of significant health-care challenges on the island that stem from Maria. And even as recovery stretches on, the bodies are counted, and the public-health system scrambles to avoid capsizing, the next hurricane season looms just a couple months away.

Puerto Rico was in the grip of a public-health crisis well before Maria barreled ashore in September. Zika had become endemic in the humid, tropical climate over a year before, and like many of the illnesses emerging on the island, it took advantage of a health-care system that lay in shambles. The major—and ongoing—financial and energy crunch that forced Congress to pass a bailout bill in early 2016 also hamstrung many health-care facilities. During his visit to Puerto Rico in May of that year, then-Treasury Secretary Jack Lew toured a major hospital with leaking ceilings, faltering electricity, supply delays in life-saving medications, and a backlog of dialysis patients. It was emblematic of a health-care system hobbled by crumbling infrastructure and evaporating municipal funds.

But even when the lights are on and hospitals run smoothly, demographic, geographic, and political features all contribute to a slate of inherent health challenges. Puerto Rico has experienced mass outmigration to the mainland over the past few decades, leaving behind on the island a population that is disproportionately elderly and sick. Puerto Rico has a health profile more akin to developing countries and poor communities of color than to the United States as a whole. Infant mortality has always been higher on the island than on the mainland. The infectious-disease burden is also higher than on the mainland, with forests and damp places on the island serving as reservoirs for old tropical-fever diseases that have all but been forgotten on the north side of the Caribbean.

In all, what Hurricane Maria encountered was a system perched only a small disaster away from complete chaos. But the hurricane was a very large disaster. The lackluster and slow federal response, the lack of coordination between different levels of government, the Puerto Rican Power Authority’s complete failure, and the ongoing Congress-imposed austerity plan all contributed to a months-long power outage and a drawn-out, patchwork recovery—one punctuated by a total blackout last week. Even in the best of circumstances, Maria would have created a public-health catastrophe, but what ensued was worse than it needed to be.

Doctors initially performed surgery in darkness. Primary care and dialysis services across the island ground to a halt. People drank water from Superfund sites, and pollution and trash sprawled across the island. With many people in rural areas being exposed to contaminated water, Puerto Rico faced a fatal outbreak of the fever disease leptospirosis. Experts sounded the alarm about the mental-health problems that could emerge as residents dealt with both the trauma of the storm and recovery, and with the deaths of loved ones and friends.

New evidence details the ongoing public-health fallout from the storm over half a year later. An April commentary from Pennsylvania State University researcher Alexis R. Santos-Lozada in Health Affairs indicates just who’s been at risk in the post-Maria landscape:

In particular, we have found that the excess deaths were concentrated among older age groups. For example, among people in Puerto Rico ages seventy and older, the death rate for the period September-October was 27 percent higher in 2017, compared to previous years. Excess deaths were also concentrated in nursing homes (where the numbers of deaths were 45 percent higher in 2017 than in 2016) and emergency departments (where there was a 41 percent increase).

A comprehensive analysis released yesterday by the Kaiser Family Foundation  finds evidence of significant progress since last winter, but also some lingering problems settling in. A series of interviews with residents and other stakeholders found a heavy reliance on temporary shelters and tarps among many Puerto Ricans, continuing financial instability, and disruption of daily health care. The sole constant for many people is that there are no constants; no real ability to set health-care routines and engage in healthy behaviors.

The most recent blackout again disrupted lives, while exposing thousands to hazardous pollutants. “I was in Ponce and the sewage water was flooding the area,” recalled Ruth Santiago, an environmental lawyer at the Inter American University Law School in San Juan. “Schools are out. Courts are closed. The big mall is closed … The water pumps stop working because there’s no electricity, so raw sewage [was] backing up.”

The rolling blackouts and damaged infrastructure are just one component of the health-care situation. The Kaiser Family Foundation report highlights the accelerating outmigration since the storm and the resultant aging and sickening of the island’s population.“The Puerto Rican government projects a 10.9 percent cumulative decline in population over the six years following the hurricanes,” it said. An NPR story finds that among the remaining elderly residents, access to long-term support and nursing is declining.

KFF also reports that the physical health needs of those remaining on the island have increased since the storm. While major outbreaks have been contained or averted, “some individuals experienced worsened chronic conditions, such as diabetes and hypertension, due to gaps in care and medications following the storms.” With reduced access to quality food, exercise, and healthy lifestyle choices, stress-linked conditions like ulcers, orthopedic problems, and weight gain are increasing in prevalence. Other reports find that dialysis patients—especially in rural places where local hospitals have been destroyed or incapacitated—are facing worsening outcomes.

Perhaps the most alarming finding is the increased burden of mental-health problems following Hurricane Maria. KFF found “sharp increases in depression, anxiety, panic attacks, and post-traumatic stress disorder (PTSD) among the communities they serve.” Again, these problems heavily affected the most vulnerable. “Some interviewees pointed to ongoing emotional struggles among children, noting that some become very fearful and cry every time it rains,” the report notes.

Mental-health professionals are noticing a marked increase in suicides. According to the Kaiser Family Foundation, “from November 2017 through January 2018, a crisis hotline run by Puerto Rico’s Department of Health received 3,050 calls from people who said they had attempted suicide, a 246 percent increase compared to the same time last year. In the same three-month period, the hotline received 9,645 calls from people who said that they had thought about attempting suicide—an 83 percent jump from the same time last year.” These findings are supported by a March story from Quartz, which found suicides up by a third compared to the same time period in 2016.

This slowly unfolding public-health crisis lacks the drama of the major outbreaks predicted in the immediate aftermath of Hurricane Maria, but presents tremendous challenges. Still, it remains possible that an improved financial plan and outlook, along with increased access to sustainable energy, assistance from the federal government, and massive public-health campaigns from the Puerto Rican government, could combine to right the ship.

The progress that has been made, though, is extraordinarily fragile. Puerto Rico simply cannot abide another hit from a hurricane while it recovers. Historical luck is on its side—for being smack dab in the middle of the Atlantic’s hurricane alley, it’s faced remarkably few direct hits from major storms over the past few decades—but the fate of public health on the island depends mostly on the hope that those historical winds keep on blowing. It’s unclear if Puerto Rico will even know how many people died from the last hurricane season before the next one begins in June.

We want to hear what you think about this article. Submit a letter to the editor or write to letters@theatlantic.com.