Author(s): Angelo Verzoni. Published on May 1, 2017.

Chased by Flames

As the 75th anniversary of the Cocoanut Grove fire nears, an ongoing research project seeks to uncover how the fire moved so fast


In the weeks following the November 28, 1942, Cocoanut Grove fire, which killed 492 people who were inside the swank Boston nightclub at the time, survivors described to investigators the terror as flames seemed to chase after them.


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“As we went up the stairs, the fire went all over the ceiling and was coming after us,” Leroy S. Marks of Boston told investigators, according to records released publicly by the Boston Police Department in 2012. Similarly, Roland Sousa of Salem said, “We made for the stairs, [and] the flames were on my heels and crawled right along and spread out and then started smoking.”

The blaze began in the club’s Melody Lounge, located in the basement of the building, then raced up a set of stairs and across the entire first floor—a distance of roughly 225 feet—in just five minutes. The question of what caused it to move so fast has remained unanswered for nearly 75 years.

But a joint project currently being conducted by the Fire Protection Research Foundation (FPRF) and Worcester Polytechnic Institute (WPI) may be helping fire engineers and historians better understand some of the more puzzling aspects of the fire’s behavior.

The project provides students taking WPI’s fire modeling course with the opportunity to apply modern fire modeling techniques to the decades-old fire. “Really going through this fire with the students has given us a better feel for how the fire went from one end of the building to the other,” said Casey Grant, executive director of the FPRF. “It was a very fast fire.”

NFPA Conference Session
NFPA Conference & Expo, Boston, June 4-7, 2017

The Unsolved Mystery of the Cocoanut Grove Fire
Tuesday, June 6, 11–Noon

Casey Grant, NFPA; Nicholas Dembsey, Worcester Polytechnic Institute

The project provides students with two weeks to study the Cocoanut Grove fire and apply modern fire modeling techniques like computational fluid dynamics to it, according to Nicholas Dembsey, who teaches fire modeling at WPI and whose students participate in the project. “It’s a great case to use with the students,” Dembsey told NFPA Journal. “A lot of times, when you’re trying to do fire modeling, you’re looking at fire investigation reports and there’s a lot of missing info. With this case, it’s well-documented and it has certain unique features, and that allows students to learn more about fire modeling.”

Grant and Dembsey will speak about the fire and the FPRF–WPI project during an education session at the Conference & Expo.

For the first two years of the project, in 2014 and 2015, students were tasked with figuring out how big and how hot the fire had to be to travel as far as it did, Dembsey said. This year, students were asked to do the same but also to come up with building changes that could have prevented the fire’s spread, he said. (The project was not held in 2016.) Despite the three years’ worth of student research, there is still no definitive answer to why the fire spread so rapidly.

But finding one isn’t necessarily the primary goal of the project, Grant said. Instead, its main purpose is to serve as a learning opportunity and selling point for students who are considering a career in fire protection engineering. Besides, finding an answer to that question might not even be possible. “I don’t know if we’ll ever solve the mystery of the Cocoanut Grove fire,” Grant said. “But this project gives students the opportunity to learn and apply techniques to the fire that weren’t available in 1942.”


Grant first dug deep into the Cocoanut Grove fire in 1991, when he wrote an NFPA Journal article ahead of the fire’s 50th anniversary. As he interviewed survivors, a firefighter, a serviceman, and the emergency room physician who treated the wounded, he was struck by the many details corroborating the fire’s rapid spread. “This thing traveled so fast in the early stages—dramatically fast,” Grant said. “It defied all logic.”

It also behaved unusually in other ways. Unlike in the Station nightclub fire in Rhode Island in 2003, where essentially everything and everyone trapped inside was incinerated by the fast-moving, extremely hot fire, the Cocoanut Grove fire left combustibles like wooden furniture and palm trees unburned. “Much of the cloth, rattan and bamboo contained in the Melody Lounge, and on the sides and lower walls of the stairway leading therefrom, was, in fact, not burned at all, and the same is true of the carpet on the stairway, contrary to all usual fire experience,” then–Boston Fire Commissioner William Arthur Reilly wrote in his report on the fire.

Cocoanut Grove Escape Path Illustration

Fast + Furious A diagram created shortly after the 1942 Cocoanut Grove fire depicts a cutaway view of the club's ground floor, with paths of fire spread added by NFPA Journal. The green circle at bottom center shows the spot in the basement, in the Melody Lounge, where the fire is thought to have begun, possibly the result of a match dropped into a decorative potted plant. The fire spread through the lounge before climbing the stairs at bottom right and racing through much of the main level. The club's only entrance was a revolving door that quickly became jammed as patrons attempted to exit the building. The fire killed 492 people. Photograph: NFPA

Reilly also described the fire’s rapid spread. “When the flame appeared in the street floor lobby it was described as traveling rapidly as ‘a ball of fire’ below the ceiling,” he said.

Grant explained that while no theories for the fire’s rapid spread have been discounted, one has gained more traction in recent years. The theory suggests a leak of methyl chloride, a flammable refrigerant being used by the club at the time, may have caused the rapid fire spread. Because the United States had entered World War II less than a year before, nonflammable chlorofluorocarbon refrigerants like Freon were in short supply, so the club was using methyl chloride instead.

But there’s a hole in this theory, Grant said. Methyl chloride is nearly three times heavier than air, so if it had been leaking, why didn’t it sink to the ground? The fire, on the other hand, was described by witnesses as spreading in high places like on the ceiling and on the tops of the club’s decorative palm trees.

Even the cause of the fire is listed as “unknown” in Reilly’s report. Ignition theories include faulty wiring, accidental ignition by a busboy’s match, and more. Whatever the cause, that’s not the main concern of researchers today, including the WPI students, because more valuable lessons can be learned from trying to figure out why the fire behaved as it did, Grant said.


One of the few things that is obvious about the Cocoanut Grove fire is why so many people died. The club was packed with about 1,000 people on the night of the fire, and, as Grant put it, “every way out of the place had something functionally wrong with it.” The main entrance and exit, for example, was a revolving door. As hundreds rushed to get out of the club, the doorway became jammed. Many bodies were later recovered from that location.

The fire had a lasting impact not only on Boston, but on the rest of the country, too. Building codes were revamped, most notably in the areas of exits, combustible materials, emergency lighting, and automatic sprinklers. Many jurisdictions began classifying nightclubs as assembly occupancies. The medical field also saw changes as a result of the tragedy. Burn treatment shifted from the painful and ineffective tanning method to the practice of gauze wrapping, and advancements were made in blood transfusion, respiratory management, and the treatment of infections. For more on the fire's legacy, visit the Cocoanut Grove fire website.

Cocoanut Grove remains the deadliest nightclub fire in U.S. history.

ANGELO VERZONI is staff writer for NFPA Journal. Top Photograph: Adrienne Albrecht