History This Week: "The Great Boston Molasses Flood"

Air Date: January 12, 2026
Host: Sally Helm
Guest Expert: Steve Puglio (author of Dark Tide: The Great Boston Molasses Flood of 1919)

Overview

This episode dives into one of America’s strangest and most overlooked disasters: The Great Boston Molasses Flood of 1919. Host Sally Helm explores how a 50-foot-high, 2.3-million gallon molasses tank burst, turning the North End into a sticky hellscape—and how the tragedy eventually led to major reforms in building safety and regulation. Guest Steve Puglio guides listeners through the disaster, its causes, and its far-reaching historical legacy.

Key Discussion Points & Insights

Setting the Scene (01:34–06:06)

• Boston’s North End in 1919:
  The neighborhood was tightly packed—40,000 people living in a square mile, mainly recent immigrants (Irish, Jewish, Italian). Commercial Street, the industrial hub, was regularly packed at lunchtime.
• The Giant Molasses Tank:
  A 50-foot-tall steel tank held 2.3 million gallons of molasses, originally intended for making explosives during World War I. With the war over and Prohibition looming, the company switched to producing rum.

The Disaster Unfolds (07:24–09:48)

• Tank Failure:
  Boston police patrolman Frank McManus witnessed the tank's collapse:
  • “He hears what he describes as a tremendous rumbling, grinding sound and the rat tat tat of what sounds like machine gun bullets... The rat tat tat are the thousands of rivets that hold together the steel plates of the tank.” —Steve Puglio (07:36)
  • McManus’s urgent call: “Send all available rescue personnel immediately. There’s a wave of molasses coming down Commercial Street.”
• The Wave:
  The molasses burst forth at ~35 mph, initially 35 feet high. It obliterated everything in its way—people, carts, horses, buildings.
  • “The entire North End waterfront is obliterated.” —Steve Puglio (09:40)

Why the Disaster Wasn’t a Surprise (12:31–14:04)

• Ignored Warnings and Powerless Community:
  Residents, mostly Italian immigrants, had little political influence. The tank leaked from the start:
  • “Kids in the neighborhood would collect molasses in pails as it pooled around the bottom of the tank.” —Narrator (12:35)
  • “When the tank begins to leak... there is almost no official outrage at this and almost no neighborhood outrage at this.” —Steve Puglio (13:58)

The Aftermath (14:04–16:42)

• Devastation and Rescue:
  21 people died, 150 seriously injured. Rescuers struggled, often stuck in thigh-high or deeper molasses, which filled basements and streets.
• Cleanup Struggles:
  Water, shovels, torches all failed; only salt water from Boston Harbor managed to wash away the sticky mess—millions of gallons flushed out.
  • “The harbor was brown for months afterwards. And years, even decades later, the locals would say that on hot days you could still smell [it].” —Narrator (16:44)
• Personal Stories:
  • “A banana salesman... had stashed over $4,000 in his shop basement and he wanted to get it back. He did. Once the cleanup crews dug out a solid 12ft of molasses and debris.” —Narrator (16:25)

The Legal Reckoning and Its Legacy (17:21–20:36)

• The Lawsuit:
  110 civil suits consolidated into a major class-action against USIA, the tank’s owner—one of the first big corporate liability lawsuits in US history.
  • “This was the first significant class action against a major US Company. The Gulf spill lawsuit. Enron, Erin Brockovich. This case paved the way for all of that.” —Narrator (17:48)
  • Expert testimony played a key role; the case lasted over five years and became a precedent-setter for engineering and construction regulation.
• Systemic Change:
  The most enduring outcome was the institution of mandatory engineering oversight and building codes:
  • “You might take it for granted that plumbers have to be certified and engineers are held responsible for the structural integrity of what they build. But that just wasn’t a thing before this case...” —Narrator (18:38)
  • “All of these things were made possible and made into law because of the great Boston molasses flood of 1919.” —Steve Puglio (19:58)

Notable Quotes & Memorable Moments

• On the disaster’s absurdity and horror:
  “When you first hear about the Boston molasses flood, I think it produces a little bit of a giggle, but it is really a terrible disaster.” —Steve Puglio (07:32)
• On how disaster led to reform:
  “Almost everything we take for granted in the building construction industry... made into law because of the great Boston molasses flood of 1919.” —Steve Puglio (19:58)
• On neighborhood powerlessness:
  “Most of them do not speak English. Most of them are not citizens. So they have very little to say in the way of political advocacy.” —Steve Puglio (13:07)
• On the long legacy:
  “Years, even decades later, the locals would say that on hot days you could still smell.” —Narrator (16:44)

Timeline of Important Segments & Timestamps

• [01:34] Introduction to Boston’s North End & the molasses tank
• [07:30] Steve Puglio describes the tank’s failure and rescue efforts
• [12:31] Local warnings and the marginalized Italian immigrant community
• [14:44] Devastation, rescue, and cleanup efforts
• [17:48] The lawsuit and its national significance
• [19:58] Steve Puglio on the regulatory legacy of the disaster

Tone & Style

The episode maintains a respectful, clear-eyed tone. It balances the initial oddity of a "molasses flood" with reverence for the lives lost and recognition for the hard-won safety reforms that followed. The storytelling is detailed yet approachable, blending narrative with expert insights.

Summary

The Great Boston Molasses Flood of 1919 was not only a bizarre and deadly incident, but also a pivotal moment for worker safety, corporate accountability, and building regulation in the US. The episode, anchored by Sally Helm and historian Steve Puglio, brings to life the texture and tragedy of the North End disaster, and uncovers how this sticky catastrophe influenced laws—and saved lives—for generations to come.