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Boston in the 19th century -

Boston's oceanfront location made it a busy east coast port. By the mid-19th century the city's population had reached nearly 450,000, its numbers swelled by the first wave of European immigrants (mostly Irish).

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Great Boston Fire of 1872 -

On November 9, 1872, a devasting fire ripped through Boston's downtown and financial districts.

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Source of the fire -

Investigators later ascertained that the blaze broke out in the basement of a warehouse storing dry goods in Summer Street (pictured).

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One disaster preceding another -

The conflagration killed at least 30 people and still ranks as one of the most costly fire-related property losses in American history. Less than 50 years later, Boston would suffer another major disaster.

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Boston expands -

In the wake of the fire, workers and engineers used building rubble as landfill along the downtown waterfront. This created significant parts of the South End, the West End, the Financial District, and Chinatown. Boston continued to expand through land reclamation and more newcomers arrived—Germans, French Canadians, Italians, and Russian and Polish Jews.

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Boston's North End -

By the end of the century, Boston's core neighborhoods were synonymous with ethnically distinct immigrants. Italians became the largest inhabitants of the North End (pictured).

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Boston Harbor -

Boston and its harbor had long served as a significant stop in Atlantic trading routes. In fact, at one point Boston was one of the world's wealthiest international trading ports.

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Major hub of trade -

The city was, and still is, a major commercial fishing port, the hub of trade centered on the famous Boston Fish Pier.

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The molasses trade -

A lucrative import was molasses, a byproduct obtained from the refining of sugarcane or sugar beet juice into sugar.

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What is molasses? -

Molasses is a thick, dark, viscous syrup. Sweet and earthy, it's used to make brown sugar and as a flavoring in many baking and cooking recipes. It's the principal ingredient in the distillation of rum, and a few beer styles such as stouts and porters also utilize molasses. Ominously, molasses is a key component in munitions.

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Versatile product -

In the 1700s, Boston and many other colonial areas were importing huge qualities of molasses. It was a profitable trade and was still flourishing in the early 20th century, the refined product finding its way into the city's bars and cafés.

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Winter of 1919 -

The early winter of 1918-1919 was bitterly cold. Snow blanketed the ground and temperatures hovered around 40°F (4°C). Then on January 15, the mercury began to rise dramatically.

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Molasses storage tank -

At the Purity Distilling Company facility in Boston's North End, a considerable amount of molasses was stored in a huge tank (pictured), in fact 2.3 million gallons (8,700 cubic meters).

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How did the flood occur? -

The previous day, a cargo vessel had delivered a fresh load of molasses, which had been warmed to decrease its viscosity for transfer. It was promptly unloaded into the tank.

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A tsunami of syrup -

What happened next was likely due to the thermal expansion of the older, colder molasses already inside the tank. Whatever the reason, in an instant the giant tank ruptured with a mighty crash sending a colossal tsunami of thick, sugary molasses barreling down the streets of North End.

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Widespread destruction -

Standing in the path of the dark tide of deadly syrup was Boston Elevated Railway's Atlantic Avenue structure.

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Enormous force -

The wave was of sufficient force to drive steel panels of the burst tank against the girders of the elevated railway, leaving it twisted and buckled.

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Swift and deadly -

Gathering momentum and reaching speeds of up to 35 mph (56 km/h), the thick liquid swept nearby buildings clean off their foundations.

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No time to react -

A fire station (pictured), its crew given too little time to respond to the unfolding disaster, was reduced to rubble.

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Devastating consequences -

The molasses flooded streets, smashed buildings, crushed vehicles, and trapped horses. In total, 21 people were killed in the catastrophe, most of them in the vicinity of Commercial Street. Around 150 were injured.

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Headline news -

The Great Molasses Flood made national headlines. The Boston Globe's late edition reported on the incident, when final casualty figures were still to be determined.

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Search for survivors -

In the aftermath of the flood, welders were brought in to carefully cut up the tank in the search for victims.

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Effected premises and infrastructure -

Detail of molasses flood area: 1. Purity Distilling molasses tank; 2. Firehouse 31 (heavy damage); 3. Paving department and police station; 4. Purity offices (flattened); 5. Copp's Hill Terrace; 6. Boston Gas Light building (damaged); 7. Purity warehouse (mostly intact); 8. Residential area (site of flattened Clougherty house).

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Molasses flood area -

Circled in red on this map detail of modern downtown Boston is the molasses flood area.

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Emergency response teams -

The Boston police, the fire department, army and navy personnel, and members of the Red Cross were all involved in rescue and cleanup operations.

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Cleanup -

Even though fire crews constantly sprayed water across the twisted wreckage, it wasn't until the city ordered powerful streams of salt water from a fireboat stationed in the harbor that the gooey carpet of molasses began to disappear. Sand was also used to absorb it. However, the odor of molasses lingered in the area for decades.

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Reassessment -

In 2014, analysis of the disaster undertaken by a senior structural engineer in Massachusetts concluded that the tank's steel walls were too thin to support the weight of a full tank of molasses. Flawed rivet design was another problem.

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Remembering the tragedy -

Today, the site of the circular tank stands in Langone Park. The anniversary of the flood is often commemorated with a memorial service for those who lost their lives. A small plaque on nearby Commercial Street serves as a historical marker.

Sources: (History.com) (NPR) (Boston Magazine) (Demographia) 

See also: The worst floods in history

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