New Orleans’ Memorial Medical Center during Hurricane Katrina was a surreal hell: penetrated by fetid floodwaters, generators kaput, sporadic communications, erratic leadership issuing countermands, animals barking inside, gunshots outside, unsanitary lavatories, sick and dying patients in the halls, sleep-deprived staff, oppressive heat and the intermittent arrival of rescue helicopters at an unmaintained helipad. The chapel became a makeshift morgue. More than one witness said it was straight out of a disaster movie.

In the midst of this miasma, real doctors and nurses made decisions that shortened the lives of real patients. Sheri Fink’s Five Days at Memorial: Life and Death in a Storm-Ravaged Hospital (which Kirkus starred) is the breathtaking, definitive account of an American hospital’s worst nightmare. The book builds on “The Deadly Choices at Memorial,” Fink’s 2009 ProPublica article on the same subject, which was the first work of online journalism to win a Pulitzer Prize. (The piece was co-published by the New York Times Magazine.) For the book-length narrative, Fink interviewed approximately 500 people, including doctors, nurses, patients, family members, emergency services personnel, government officials and investigators.

Not all involved were willing to talk. “There are many people committed to the idea that this story should not see the light of day,” Fink says. Those people thought, “ ‘It happened. We need to put it behind us.’ ‘People could get in trouble.’ ‘What if somebody reopened the case?’ There’s all sorts of fear out there. Because of those stakes and being very aware of them, I felt a huge burden of responsibility to try to get it right and to also let people know what I was saying about them and give them the chance to make sure that it sounds right to them or to explain it from their perspective,” says Fink, who attempted to contact everyone mentioned in the book ahead of publication.

What happened, in part, was this: Dr. Anna Pou and nurses Lori Budo and Cheri Landry administered lethal doses of palliative medicines, morphine and a benzodiazepine sedative, to patients of LifeCare, a hospital within the hospital, designated for the complex’s sickest residents. These desperate times were met with disparate efforts from hospital staff: A few abandoned ship; others evacuated with their patients. Many of those who stayed, including registered nurse Cathy Green, kept up care as usual. “Green saw the sick lady before her as somebody’s mother, somebody’s grandmother,” Fink writes. “Many people probably loved this lady. Green felt love for her, and she didn’t even know her. The woman was precious, whether she had six months to live, or a year to live, whatever it was.” Isn’t that what we’d want for ourselves?

It is possible that, days into the crisis but not entirely certain that help was on the way, the “Memorial Three” believed they were acting in the best interests of patients in varying states of ill health. Some patients were unresponsive. At least one, however—Emmett Everett, a paraplegic 60-year-old awaiting bowel surgery—had been alert, aware and anxious to be reunited with his family earlier that day. At an estimated 380 pounds, his size precluded easy egress from the hospital’s eighth floor to a rescue vehicle. But what did he want for himself?

Fink artfully interweaves different opinions and remembrances of the same events into two distinct sections: “Deadly Choices,” a retelling of the events as they unfolded, and “Reckoning,” a detailed analysis of the aftermath, including the legal ramifications of the physicians’ and other caregivers’ actions. By incorporating so many threads, she provides for a gamut of perspectives. One universal experience of Hurricane Katrina at Memorial was fear. “[Americans] don’t deal with these types of Spartan situations very often, and it is true that our medical profession is now very dependent on technology and very dependent on electronic medical records,” Fink observes. “There’s very little of the just kind of hands-on, old-fashioned medicine anymore, [and the adverse conditions] really stunned them. It really made some of them panic.”

Hospital operations suffered severely from a lack of disaster preparedness. This is not a local problem: National regulations for hospitals are lax. Generators are not required to be tested for long-term viability and are often located on first-to-flood floors. A successful interagency chain of command has yet to be defined and implemented. “Doctors and nurses were suddenly thrust in the horrible situation [without] guidelines for who gets the first seat on the rescue helicopter when the rescue helicopters are coming slowly,” says Fink. “I think [this is among] the questions that we should all be thinking about, that we should all have a say in.”

Fink’s perspective is especially well-informed. She is a trained physician who spent time in a Bosnia-Herzegovina war hospital and in Haiti after its devastating earthquake in 2010. She is well-acquainted with the concept of triage, a rationing of medical resources based on patients’ prognoses—the instrumental concept in deprioritizing evacuation of the LifeCare patients. “Who decides how care is allocated is critically important because it is, at its heart, a question of moral priorities,” Fink writes. And: “Life and death in the immediate aftermath of a crisis most often depends on the preparedness, performance and decision-making of the individuals on the scene.” The patients got Pou, Budo and Landry. In turn, Pou, Budo and Landry got arrested on four counts of principal to second-degree murder, and a grand jury investigation ensued.

More than a chronicle, Five Days at Memorial is a call to arms illuminating the critical need to create effective policies and guidelines for health care professionals in large-scale crises. As Hurricane Sandy swept northern shores in 2012, it threatened to put North Shore-LIJ Health System in a similar situation—but a combination of quick thinking and creativity kept generators running and patients alive. “I just feel that we need to know the story,” Fink says. To know, as harrowing as that process may be, is the first step toward improvement, prevention and protection.

Megan Labrise is a freelance writer and columnist based in New York. Follow her on Twitter.