On January 15, 1919, a massive steel tank holding over two million gallons of fermented molasses ruptured in Boston's North End. The initial collapse launched a 25-foot-high wave of syrup traveling at 35 miles per hour, destroying buildings, crushing elevated train tracks, and killing 21 people. While a tidal wave of sugar sounds surreal, the physics that followed turned the incident into a protracted nightmare.
The temperature had risen from near zero to 40 degrees Fahrenheit the day before, accelerating carbon dioxide production inside the improperly built tank until it burst. However, as night fell, temperatures plummeted once more. This sudden cooling produced a severe viscosity shift.
The warm, flowing molasses rapidly thickened into a tar-like paste that glued victims to the ground, crushed lungs through suction, and rendered rescue equipment useless. Saltwater pumped from the harbor was the only solvent capable of breaking down the goo, but cold water turned the syrup even harder. Cleanup took weeks of manual labor and hot water scrubbing, leaving the neighborhood smelling like sweet rot for decades.