Great Molasses Flood of 1919: The 25-Foot Syrup Wave That Killed 21 episode artwork

EPISODE · Aug 5, 2026 · 4 MIN

Great Molasses Flood of 1919: The 25-Foot Syrup Wave That Killed 21

from Understand All · host Aaron Barlow

How does a tank full of molasses turn into a 25-foot wave that kills 21 people in Boston? In this episode, we unpack the Great Molasses Flood of 1919, the engineering failure, the science of sticky fluid dynamics, and the disaster’s lasting impact on safety and building codes—listen now before this bizarre piece of history slips by unnoticed.How does a 2.3-million-gallon molasses tank become a deadly wave in Boston’s North End? In this episode, we unpack the Great Molasses Flood of 1919, the 25-foot syrup wave that killed 21 people, and the engineering failures, non-Newtonian fluid behavior, and safety reforms that followed.• The tank leaked from the start, and warning signs were ignored. • The flood moved fast at first, then thickened as it cooled. • The disaster exposed major flaws in industrial design and oversight. • The legal aftermath helped shape modern building codes and engineering accountability.Why the tank failed The science of molasses as a fluid The human cost in Boston’s North End The court case and negligence findings How the disaster changed safety rulesRelated resources: Internal: [More episodes on engineering disasters](#) External: [Britannica: Great Molasses Flood](https://www.britannica.com/topic/Great-Molasses-Flood) External: [Scientific American on the physics](https://www.scientificamerican.com/article/molasses-flood-physics-science) External: [Boston.gov historical overview](https://www.boston.gov/news/100-years-ago-today-molasses-crashes-through-bostons-north-end)If this story surprised you, share it with someone who loves weird history, and follow the show for more episodes that turn strange facts into real understanding.

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