Rediscovering the Ruins of a Catastrophic WWI Explosion Everyone Forgot

A man stands in the massive crater left by the 1918 Morgan explosion

In 1918 the United States was standing at the latter years of World War I, a conflict that tore the globe apart at the seams and let out incalculable waves of questions and fear. The munitions that brought such horrors had backgrounds as diverse as the soldiers themselves; in the United States production plants sprung up across the country in order to meet the product demand.

One small town transformed by the need for munitions was Morgan, New Jersey, and in October of 1918 the town would feel the horrors being delivered overseas when a massive explosion rocked the central coastline, plunging it into a raging inferno.

Gillespie plant power house in July 1918

The T.A Gillespie Company Shell Loading Plant was one of many constructed in New Jersey as Middlesex County was a prime location situated on the coast. Despite the seaside advantage, some were uneasy with the placement of the Morgan facility due to its proximity to towns, something normally avoided with the construction of a munitions factory. When production began in June of 1918, the massive complex covered approximately 2,200 acres including ­­­­700 buildings used for the complicated process of manufacturing explosives. Composed of galvanized steel, concrete, and brick, some buildings were constructed to be protected against accidents and explosions. Brick firewalls were installed in buildings with loading rooms, melting kettles, and ammonium nitrate/TNT storage, and service magazines (each capable of storing 150,000 pounds of TNT) surrounded by earth-filled bulkheads served as a buffer should an explosion occur. Other structures meant for the storage of completed shells were constructed of wood and concrete, a use of materials that would be criticized in the days following the disaster.

It was 7:40 pm on October 4, 1918 that Morgan, New Jersey, and its surrounding towns felt the earth shake. The Gillespie Plant’s building 6-1-1 exploded into a raging fireball, cutting power and severing water mains. Firefighters arriving on scene faced severely depleted water pressure and were left helpless while the fire ignited other magazines, which caused further destruction. Additional firefighters were unable to access the plant’s hydrants situated in between and near buildings that were igniting. Plant employees flew into a panic and those that could ran, leaving behind all belongings in their attempts to escape. Shells whistled through the air and fires shot into the skies while people scrambled in the punctuated darkness looking for escape while trying to avoid glass, shrapnel, and explosive shells falling like heavy rain.

While employees of the Gillespie plant were trying to escape the inferno, citizens of nearby South Amboy were trying to escape their town which was crumbling around them. The stream of people evacuating upon the initial explosions grew to a mass exodus with blasts shaking houses and shattering nearly every window. Residents became refugees walking the streets, seeking shelter in neighboring towns, while those who stayed were forced to camp outside out of fear of their homes collapsing. Others headed toward the burning complex in hopes of finding missing family members.

Morgan residents fleeing the explosion (via New York Times)

The now refurbished site of the Gillespie plant power house (all present day photographs by the author)

Original wall of the Gillespie plant power house

It would be days before the explosions and fires would cease and the extent of the devastation could be assessed. Of the 700 buildings at the T. A. Gillespie Loading Company, 325 were destroyed. The property was heavily pocked with craters, with one measuring 30 feet deep, 140 feet wide, and 150 feet long where an ammonium nitrate storage containing 1,000,000 pounds of the substance had once stood. Of the 30 million pounds of explosives located in the magazine storage and freight cars, 12 million pounds were destroyed, and of the over one million loaded shells on site that night, over 300,000 were detonated or destroyed.

Though the material loss was astounding, the human toll was devastating. The nature of the disaster made an exact death toll difficult to confirm (there were accounts of family members disappearing that night without a body ever being found), but it is estimated that approximately 100 people died on the grounds of the plant. Of the estimated 62,000 people who were displaced by the explosions and left with little protection against the elements, nearly 300 people would die as the result of a flu epidemic sweeping the area around the time of the incident.

Remains of the Gillespie plant

Exterior of a surviving Gillespie plant building

Another view of the plant building

Theories about the cause of the accident spread as quickly as the fires, with some wondering if this was an act of sabotage. Days later T.A. Gillespie himself spoke to newspapers, describing his belief that a kettle of amatol — a mixture of TNT and ammonium nitrate — had overflowed, resulting in the first blast despite employee efforts to keep the material under control. A later investigation by the army determined that the blast was not preceded by a fire and had occurred without warning. Further investigation confirmed that the initial explosion occurred in building 6-1-1, and subsequent explosions occurred in areas including shell storage, shipping cars, and finishing rooms causing massive fires and the launching of shells. An official cause of the explosion was never confirmed.

The blast that shook central New Jersey is now a faded memory, with many current residents unaware of what happened in their town. Of the 700 plant buildings, only two remain, hardly recognizable in their transformation into local businesses and as part of a marina. The Ernst Memorial Cemetery located in Parlin New Jersey is home to a memorial honoring those lost in the explosion. Erected in 1929, a stone sits above a mass grave reading: “In memory of the unidentified dead who gave their lives while in the service of the United States of America, at the Morgan Shell Loading Plant in the explosion of October 4-5, 1918.”

Memorial stone and mass grave for those killed in the Gillespie explosion 

It is in this 20 foot by 35 foot grave, and within the few remaining walls of the ruined buildings, that the last memories of a terrible event that shook New Jersey rest, reminders that the tragedies of war can turn any location into a site of unspeakable disaster.

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