Episode Description: On July 2, 1918, an explosion would claim the lives of over 50 people, injuring many more in Syracuse's suburb of Camillus, New York. The explosion of the munitions factory in Split Rock Quarry had the potential of taking out the city of Syracuse and there are still many unanswered questions as to what led to the fire and the subsequent explosions to this day. In this episode, we dive into the history of the quarry as well as some of the theories into what led to the tragedy. We also touch on a the history of the Hart's-Tongue fern and the famous Pinkerton Detective Agency, who helped paved the way towards modern law enforcement. 

Original Publication Date: July 21, 2024

Date Page Last Updated: July 16, 2024

The settlement of Split Rock was established by Irish immigrants in the 1700s. The name of Split Rock Quarry stuck for a few reasons. First, French-Canadians that lived in the nearby settlement of Rockville that were working in the early quarries where the larger Split Rock Quarry would eventually become were reminded of a Split Rock that they would pass on their way from Canada. They would pass an area where the Hudson River split two hills, in Split Rock there was a gully with a bit of stream through it that split two mountains of stone. One of the two ‘mountains’ in the Quarry would be named Canada hill. Split Rock is also a quarry term, so between the two the name stuck for the quarry. Split Rock Quarry originally started out as a limestone quarry in 1796. Some of its major contributions at that time was building the original Erie Canal, as well as several other locks and canals in the state and even provided a stone for the Washington Monument. The quarry itself was active for a century before being repurposed by Semet-Solvay. 

Semet-Solvay Company was a Belgian company that made chemicals. In the 1860’s Belgian chemist Ernest Solvay developed the modern form of producing sodium carbonate, also known as soda ash, which is used today in a large number of manufacturing processes such as glass, lithium-ion batteries, food and pharmaceuticals. The two ingredients for this are salt brine and limestone. The lectures I watched on the Onondaga Historical Society’s YouTube channel went more in depth with how this worked, so if you’re interested in finding out more about that, I’ve linked them further down the this page. The Solvay’s would license two Americans, William B. Cogswell and Rowland Hazard to produce soda ash in the US, and they would partner them to start the Solvay Process Company in 1884 and they built their production plant in what is now Solvay, NY which is a bit northwest from the quarry. As time went on the company started to move things closer to the quarry. 

TNT started to be produced by Split Rock Quarry in 1900. By 1907, a picric acid plant was relocated to Split Rock Quarry to help protect the process of making the chemical from competitors. They wanted it in a more isolated spot to help ensure their patents were safe. This will come back into play later in the story.

On July 28, 1914, World War I began and because of this the Semet-Solvay Company would establish an ammunition facility in Split Rock Quarry in 1915. In addition to the TNT and Picric Acid, other products of war were also in production here, including poison gasses. By 1918 about 2,500 people were working in the facility. The munitions factory at Split Rock was instrumental to the first World War, which I had no idea about. Most of the people working at Split Rock Quarry were either older than 50 or as young as 13-14 years old since most of the men in the area had joined the war. Several of the foremen were in their teenage years. 

Many of the workers in the Picric Acid factories were women. Working with the Picric Acid was extremely dangerous. The product would turn their skin yellow, giving them the nickname 'canaries'. The yellow coloring would fade over time once they left the work in the factory. The dust from the Picric Acid was extremely explosive and would detonate if anything iron oxide in nature touched it. One factory exploded when a plumber came to fix a pipe and his wrench touched the dust from the picric acid that had settled on the leaking pipe. 

The first explosion at Split Rock Quarry happened on February 18, 1916. Semet-Solvay company had hired an under-qualified chemist to run the company sometime around December 1915. The chemist decided that he could easily double the production of TNT by just doubling the batches, except he neglected to account for the additional fuel and pressure that would be produced by doing this. Due to the increased pressure, a tank would explode, throwing five men through the brick walls of the building. Due to the weather at the time, being February, it was very difficult for first responders to try to get to the factory to try to help the men. One of the men who died was working his first night in the factory, the other man had only been there a few weeks. 

 The explosion in 1918 occurred for a different reason, it started in part because of a fire. Fire was not uncommon at Split Rock Quarry, according to Richard Miller they happened every couple of days and the men were well prepared to deal with them. They had fire drills frequently. There were gravity water tanks on site for them to have good access to water to douse the flames. But one very important thing that the company had skimped out on was sprinklers. The building that the fire started in on July 2, 1918, per state regulations should have had sprinklers due to its height. The building was truly three stories high, but the company had managed to get it classified as a one-story building. The building was very open, instead of having different floors, there were catwalks for the second and third levels of the building. The company would tell the state that the workers didn’t go up there and that was basically how they had gotten around the sprinklers. Had there been sprinklers, it’s likely that the tragedy that was about to ensue would not have happened. The production of TNT in this building meant that there were constantly explosive fumes in the building as well. On the night of July 2, 1918, it’s believed that what started the fire was an overheated gear in a grinding machine- though there would be prevailing rumors of other causes which we will get to in a little bit. The building was not attended at the time, but the workers quickly became of the fire and got to work trying to extinguish it with hoses around 8:30 pm. The fire would quickly spread to the structure of the building becoming out of control. To add to the problems that the workers were having trying to put this fire out, they began to have issues with the water pressure. The water pressure issues would lead to a lot of speculation later that the explosion was due to sabotage, because there were conflicts in the reporting as to when the water pressure issues started. The issues with the water pressure occurred because they had multiple hoses attached pulling from the same water source so while they didn’t lose water pressure, they lost Nossal pressure which meant that the water wasn’t shooting out as far as it had been. The men are told to then run for their lives. They valiantly fought the fire for as long as they could because there was a very real concern that it would spread to the picric acid production buildings and across the gully to Canada Hill where they had the production buildings for poison gases, and if that exploded a poison gas cloud could descend upon Syracuse. 

60 men are officially on the record as having died due to the explosion. Initial reporting had 65 dead with 50 injured. The company did not keep record of how many men died later as a result of their injuries or due to the inhalation of toxic gases that were released during the fires and subsequent explosions. The dead included factory workers, researchers, govenment agents, and at least one soldier who's body was never found. 15 of the dead were never identified and would end up being buried in a mass gave in Morningside Cemetary in Malone, New York.

There were several theories as to what led to the explosion in 1918 including:

• A spark from an overheated gear fell into an open vat of TNT

• Some sort of 'organic material' fell into a vat of TNT

• German's sabotaged the plant

• The company blew up the munitions plant intentionally to keep the government from taking it over

The Syracuse Journal had reported heavily on the investigation into the Split Rock explosion. One interesting thing to note is that the archives of that reporting has mysteriously disappeared from the Syracuse Library- not only the reading copies, but also the back up copies have all mysteriously vanished. 

There are two reports that remain- In July of 1918, the Syracuse Journal reported that the District Attorney had testimony from workers that three men had sabotaged the plan and that those three men ‘are or were’ workers for the company, so it was an inside job. In August, there was a report for the Syracuse Journal that those men may be charged with manslaughter and would get the maximum wartime sentence. The DA’s record for this does still exist at the Onondaga County courthouse but it is contaminated with asbestos. However, a copy of it was sent to the United State Attorney General’s office. I’m not sure when that was but I’m interested to see if anything ever comes out of it. 

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