Outside it was the cold Saturday of a Thanksgiving weekend. But in the basement of the Cocoanut Grove, a Boston nightclub, revelers could imagine they were in the balmy South Seas. The barroom was filled with fake palm trees, and little lightbulbs nestled into coconut husks. About a thousand people packed the club that night, nearly double the building’s rated capacity.

Rumors later spread that the fire started when a busboy struck a match to help him see in the dark while fixing a lightbulb, and inadvertently ignited a satin canopy. One patron saw a bright flash the size of a dinner plate. A startled crush of people, rushing for the doors, found some exits inaccessible and others locked. One man fell, blocking a revolving door that served as one of the main exits from the building. Within minutes the whole building went up in flames, and 492 people died as a result.

More than a hundred survivors went to Boston City Hospital, where standard treatment for burns was to cut off blisters and bathe patients in tannic acid, which caused the tissue to harden and thus keep out infectious organisms. But at Massachusetts General Hospital, the 39 survivors who lived long enough to be treated underwent an experimental protocol. Under the direction of surgeons Oliver Cope and Francis Moore, patients were wrapped in gauze coated with petroleum jelly. The hope was that this would also prevent infection, but it could be applied more quickly and wouldn’t damage the patient’s skin.

Burn wounds disrupt the skin’s ability to regulate evaporation. As a result, burn victims can quickly lose large quantities of water and plasma (the fluid portion of blood), causing many of them to go into shock. At both hospitals, physicians tried to carefully assess the fluids that their burn patients would need and administered donated plasma—a medical technology that was then just four years old. But how much plasma to administer was still a matter of some guesswork. Cope and Moore would later publish a landmark 1947 paper establishing a formula for fluid replenishment, based on treating 19 Cocoanut Grove survivors. Their formula was based on the total surface area of burn wounds in addition to the volume of urine and liquids that had been wrung out of patients’ bedsheets. After one month, a third of those treated for burns at Boston City Hospital were dead from complications. But none died of burn wounds under the experimental protocols at MGH.

Those survivors at MGH received another novel treatment. Burn victims, especially those receiving skin grafts, were vulnerable to staphylococcal infections. In early December, under police escort, the pharmaceutical firm Merck & Co. rushed 32 liters of a medication containing penicillin from New Jersey to Boston. The antibiotic, originally discovered in 1928, was expected to offer a safeguard against infection. But penicillin existed only in an unrefined liquid broth, and while the effects of these crude intramuscular doses had proven inconclusive, its use nearly doubled the number of civilians treated—with no reported toxic side effects. Publicity about penicillin soon reinvigorated efforts to mass-produce the new drug.

Psychological treatment during the crisis also broke new ground. The January after the tragedy, one man, distraught at having lost his wife in the fire, leaped to his death. Yet the grief experienced by survivors and their families might have done far greater damage but for the work of Erich Lindemann, an MGH psychiatrist, who helped to mobilize churches and community organizations. With his colleague Gerald Caplan, Lindermann used the data he collected to develop a theory about grief patterns. Their paper became a founding text for how to provide psychological care in the wake of a disaster.

As senseless as the disaster at Cocoanut Grove was, it spurred reforms in fire safety around the country, and in its aftermath, pioneering treatments of burns and the management of acute grief (now known as post-traumatic stress disorder) were tested and proved. As the authors of a 2016 review in Journal of Burn Care and Research put it, the conceptual advances made in treating the victims of the fire “have saved far more lives than were lost in the event.”