Split Rock Explosion

A played-out limestone quarry in the hills of New York should have faded into silence, but World War I turned Split Rock into something far more dangerous: a round-the-clock TNT factory built to feed an exploding demand for high explosives. We walk through how an isolated site with rail access and existing infrastructure became the ideal place to make munitions, and why “ideal” can also mean “easy to look away from” when the goal is maximum output.

We follow the pressure cooker logic that rules the plant by 1918: nearly 3,000 workers, nonstop shifts, and a staggering share of America’s TNT production. That pressure reshapes staffing and risk, from teenagers and older workers taking critical roles to women working around picric acid so often their skin turns yellow, earning the nickname “Canaries.” Small fires become common, drills become routine, and routine turns into complacency. A 1916 explosion should have been the wake-up call, but the quotas keep climbing.

Then July 2, 1918 arrives. A fire in Building No. 1 grows at the worst possible time, water pressure fails, the building lacks sprinklers because of a regulatory loophole, and the site loses power as responders fight in near darkness. The blast kills 50, injures many more, and sends flames toward storage magazines holding roughly 1.5 million pounds of explosives, putting nearby Syracuse within a terrifying potential blast radius. We also connect Split Rock to the wider wartime pattern, including a similar TNT disaster in England, and we end on the question that still won’t go away: what do we sacrifice when production becomes the highest value?

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Transcript

A Quarry With A Dark Future

SPEAKER_00 0:00

So, what do you do with a quarry that's all played out? Once all the limestone or whatever you're mining is pretty much gone? Do you just leave all that infrastructure, all those buildings and equipment to rot where it stands? Or do you just leave it sit and wait for war to break out and use it to make and store millions of pounds of high explosives day in and day out for years and hope that nothing bad happens? Like what happened on july second, nineteen eighteen when an overheated mixer started a fire that led to an explosion that killed fifty workers at the Split Rock Quarry in New York. So what happened? I'm Andrew, and this is History's A Disaster. Tonight we're heading to the hills of New York for an explosion in a former quarry turned bomb factory in a small town in New

Rock Candy Sponsor Break

SPEAKER_00 1:04

York. And tonight's episode is brought to you by Coley's Rock Candy. Yes, that's right. Coley is back. After the success of his shaved ice business, Coley is expanding his product line to include his take on the classic rock candy. And with flavors ranging from lemon limestone and pomegranate pegmatite to the spicy ghost pepper scoria and tough habanero. Coley has a flavor for any sweet tooth.

From Limestone Quarry To Munitions Plant

SPEAKER_00 1:36

The Split Rock Quarry started out as a limestone quarry started in 1834 by Gilbert Coons, who ran it for several years before it changed hands. The Sauve Process Company took over operations of the quarry in the eighteen eighties, cutting limestones from the western hills of Onondaga County and sending it by elevated conveyor nearly two miles to their industrial plant at Sauve, New York. But around nineteen twelve, the quarry was all played out and nearly forgotten and the formerly loud site with its conveyors and crushers sat silent. Then World War I started. World War I created an enormous demand for high explosives that no other American infrastructure could meet. Britain, France, and Belgium were burning through artillery shells faster than they could make them. And the United States, still neutral and not actively participating, sat back supplying the Allies. However, new production capacity was needed right now. The Semit Salvoy Company, an affiliate of Selvoy Process, with experience in industrial chemistry, jumped at the former quarry. It was isolated, had existing buildings, right next to rail lines, and had a thousand acres of rocky terrain that would contain an accident better than any flat farmland would. It was the perfect place to mass produce the explosives that were desperately needed in the European Theater of War. By 1915, construction was underway. By the time the United States entered the war in nineteen seventeen, the production pressure intensified. Split Rock had grown drastically. The plant employed nearly 3,000 workers by 1918, running around the clock in rotating shifts. This one factory produced 25% of the entire country's TNT output. It was one of only 18 facilities in the nation, and it was shipping its deadly cargo directly to the front lines in Belgium and France, where it was being packed into artillery shells

War Demand And Dangerous Corner Cutting

SPEAKER_00 3:57

and dropped into trenches. And of course, with them producing so much of the explosives needed, they had to cut some corners. Safety was thrown out the window and really wasn't much of a thing. They couldn't slow down, couldn't stop. They had to continuously push production forward. The cost of pausing production for an inspection or retrofit or safety review is measured not just in dollars, but in shells that don't reach the front. That thought runs through every decision made inside the fence line, consciously or not. And at Split Rock, these thoughts had been shaping decisions since day one. And who runs and works at the most explosive industrial facility on the eastern seaboard? Well, mostly teenagers. By nineteen eighteen, most of the able bodied men of the area had been shipped off to fight in Europe. This left nothing but the young and the old. Most of the men working the plant were over fifty or as young as thirteen, with most of the supervisors being the older teenagers, not quite old enough to fight and die for their country, but old enough to be trusted with making high explosives. Which makes a whole hell of a lot of sense. Have you talked to a teenager recently? Imagine them making bombs. And of course, they employed a lot of women, which not a bad thing. Both World Wars greatly helped to advance women's rights and forced the government to rely on them in the workforce, which was great for all the Rosie Derivator types, not so great for the radium girls. But that's a whole other story. Now the women working here in the pickric acid sections were exposed to a compound that turned their skin a permanent yellow, earning them the nickname Canaries. And speaking of safety, fires at Split Rock have become rather common. They happen regularly every few days, mostly small, manageable fires. Fires that the gravity water tanks and the trained response teams put out before they grew to anything serious. The team knew their protocols and roles. When the alarm sounded, they knew exactly where to go and what to do. And every time the alarm went off and the fire went out and everyone walked back to their stations, they became just a little bit more complacent, which is always not a

Teen Labor And A Culture Of Fires

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good thing. On february eighteenth, nineteen sixteen, barely two months after production had begun, Split Rock experienced its first explosion. The company had hired a chemist in December of nineteen fifteen, and he wasn't exactly the most qualified person for the job. His

The 1916 Warning Explosion

SPEAKER_00 6:56

solution to increasing TNT output sounds good on paper. Double the batch sizes. However, chemistry doesn't exactly work that way. Doubling the batch size doesn't just double the output. It doubles the heat generated by the nitration reaction. It increases the pressure inside the processing tanks. And in a system already operating close to its limits, that additional heat and pressure has nowhere to go, which leads to a tank exploding. During the explosion, five men were thrown through the brick walls of the building by the force of it. Two of them died, one of them on his very first night at the plant, another after only a few weeks on the job. The plant had already shown what it could do when pushed. Two years later though, the lessons had faded. Complacency set in. Production resumed. The war continued. The quotas climbed, and the mixing motor in building number one kept running, shift

July 2, 1918 Fire Starts

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after shift, its bearing generating a little heat extra heat unnoticed, then a little more, then just slightly too much. Until the night of july second, nineteen eighteen, when the gap between what the system could hold and what it was being asked to do finally closed. The night shift on july second began the same way every evening shift began. Six hundred men spread across the site, moving through the familiar geography of the plant. The TNT buildings, the pickrick acid section, the acid storage areas, the network of paths and roads that connected them across the quarry floor. Building number one was running, the mixing motor was running. The nitrifier, the vessels inside the building where tooling was held and processed through the early stages of nitration contained at that point in the shift, roughly twenty two hundred pounds of it. Now this stuff is the industrial name for tooling in its raw feedstock form. It's a colorless, water insoluble liquid with a faintly sweet smell. It's the starting material for every pound of TNT that left the sprint lock facility. Twenty two hundred pounds of it sitting in a vessel inside a three-story wooden building being processed by equipment generating continuous friction. At eight forty PM, the alarm sounds. Something is wrong in building number one, a fire started. Most likely from an overheated gear in the mixer igniting the vapors. The vapors from the nitration process are heavier than air. They settle toward the floor, collecting in the low spaces, drifting along the catwalks. They are the reason building number one requires careful management of every ignition source. And a bearing failing inside a mixing motor? Well, that's an ignition source. The fire starts small, the kind of fire split rock has dealt with before, the kind that goes out quickly. The men responded exactly as they had to. They go where they are trained to go. They reach for the hoses connected to the gravity water tanks, positioned on the hillside above the plant, specifically to maintain pressure for exactly this

Water Fails And Sprinklers Never Existed

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reason. And the hoses go limp. The water pressure fails for a still as yet unknown reason. The men fighting the fire in building number one lost their water at the moment they needed it most. The one safety layer between a manageable fire and an unmanageable one disappeared. And what made it so much worse was building number one had no sprinklers. Now, it's not because sprinklers weren't a thing back then, or they just didn't think of it or anything like that. No, the building had no sprinklers because Sement Solvey had successfully argued to state inspectors that the structure should be classified as a single story building and doesn't meet the state's regulations that would require it to have them. Never mind that it's three stories tall with working catwalks at every level. Pay no attention to any of that. In fact, those aren't even true floors. Just simple catwalks. So no need to classify the building as anything other than a single story and make us do something like put in the required sprinklers for a multi-story building. And of course, the inspectors bought their argument. Either they didn't think it was worth the fight, or well, they probably got paid off as is often the case. So the sprinkler requirement did not apply to building number one, the building that contained the most volatile process on the entire site. The building most likely to burn or potentially explode. Yeah. Definitely nothing to worry about there, no need for any sort of extra precautions. Anyways, in the minutes before the explosion, as the fire spreads from the TNT building toward the adjacent pickrick acid section, the plant loses electricity. The men still on sight, still fighting, still trying, doing exactly what their training told them to do, are plunged into near darkness. The fire they can see clearly. Everything else disappears.

Blast Night And Syracuse Nearly Lost

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At roughly nine thirty PM, building number one explodes. The explosion throws men hundreds of feet. Some are killed by the blast pressure directly. Some by debris. Others from the gases released. No visible wounds, no burns, no impact injury. Just the toxic atmosphere of burning picric acid overwhelming everything in its radius. The men's skin where the acid had touched it stained a deep yellow. Fifteen of the over fifty men who died that night are incinerated so badly that they cannot be identified at all. Dozens more are injured, some severely. The fire is rapidly expanding from the wreckage of building number one, pushed onward by the wind out of the south across the quarry floor toward the storage bunkers on Canada Hill. Bunkers that contain roughly one and a half million pounds of explosives, finished TNT, and picric acid awaiting shipment to the front lines, stored in magazines designed to isolate them from the production buildings by distance and terrain. If the fire reaches Canada Hill, the blast radius of a million and a half pounds of high explosives would be enormous, enough to take out a small city. And downtown Syracuse, just four miles away, is right in that radius. It was close enough the streets shook from the initial explosion. People ran out of doors in confusion and fear, fear of an earthquake or a potential attack by the Germans on American soil spread through the growing crowds. And no last ditch or dramatic rescue would save the magazines on Canada Hill. No, a simple act of nature did. The wind shifted, so the fires being pushed on, stopped short and never quite made it there. Syracuse would survive, barely. By the morning of july third, building number one was gone, wiped completely off the map. The wooden building that had pumped out a continuous stream of high explosives for three years had been reduced to nothing but a debris filled crater and rubble spread across the quarry floor. The adjacent pickrick acid section was destroyed. The path the fire had taken across the site was a line of destruction moving outward from the mixing motor, through the building, into the chemical systems beside it, and then stopped by a shift in the wind.

The Dead Identified And Memorialized

SPEAKER_00 15:23

Workers came back in the daylight to find what the night had left. Charged structural members, twisted metal from the process equipment, and scattered across the debris field the remains of the men who had been inside the building or fighting the fires when the explosion came. Fifteen of the fifty dead could not be identified. The force and heat of the detonation had left nothing recognizable that a name could be attached to. The company knew who was missing. They had the employment records, shift rosters, the names of the men who had clocked in that evening and had not clocked out. They provided those names to the Onondaga Onondaga oh yeah, I'm fucking that up. Onondaga County Coroner. And the coroner working from both the employment records and the fifteen unidentifiable bodies recovered from the site was able to determine nearly a month after the explosion that the numbers matched up. On july thirtieth, nineteen eighteen, twenty eight days after the explosion, the Syracuse Herald reported the confirmed dead toll at fifty. thirty three bodies had been identified. Fifteen remained unidentified in the County Morgue on Montgomery Street. The Onondaga County Undertakers Association arranged a joint funeral for the fifteen. Fifteen hears left the morgue on Montgomery Street. Protestant, Catholic, and Jewish clergy officiated together the names on the fifteen markers preserved in Oakwood Cemetery, suggested victims of all three faiths. Men from different communities and different backgrounds brought together by the same shift, the same building, the same motor. Semet Solve erected a monument at Oakwood Cemetery, where it still stands today. The inscription reads in part in memory of those workers in munitions during the war for civilization who voluntarily gave their lives in fighting fire at Split Rock july second, nineteen eighteen. That voluntary part is such a nice touch by the company. They chose to work there and chose to face the dangers every day. Dangers the company voluntarily put them in when they chose not to install a sprinkler system or allowed the production to even slow for a second for any kind of safety precautions. But whatever.

Production Resumes Despite The Bodies

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Anyways, of course, they couldn't let a little thing like an explosion or the deaths of several employees slow them down. Within days of the explosion, the company announced it would continue production at Split Rock. The strategic logic as presented to the public and to the war effort was unassailable. The war needed those explosives, god damn it. The intact magazines across the valley were full, and the production infrastructure that had survived the explosion, the picric acid lines, the nitric acid systems, and the ancillary chemical operations were still operational. Shutting down would mean shells that didn't reach France, and we can't have that at all. It would mean a gap in the Allied supply line, it would mean failing the men in the trenches. So they couldn't stop, and that was the same fucked up logic that had created the conditions for the explosion in the first place.

A Twin Disaster In England

SPEAKER_00 18:56

And speaking of explosions, Split Rock was not the only TNT factory to explode in the summer of nineteen eighteen. It was not even the first one that week. On july first, one day before it, the National Shell Filling Factory at Chilwell near Nottingham in England was partially destroyed when eight tons of TNT detonated in the dry mix section of the factory, killing roughly one hundred and forty workers. And since England was having the same labor shortages we were, the victims included many young women who worked in the filling sections. Their skin also stained yellow from the picric acid contact in exactly the same way as the women working at Split Rock, and they even had the same nickname on both sides of the Atlantic, the Canaries. The cause of the Chillwell explosion was never officially determined. Investigators there pointed to different factors an exceptionally hot day, production demands running at maximum capacity, and safety precautions that had been allowed to lapse under wartime pressure. Sounds pretty familiar? The British government censored all reporting on the Chilwell disaster until after the armistice was signed in November of nineteen eighteen. The public didn't learn what had happened for months. Two TNT plants, two countries one day apart, both of them running at maximum wartime output, both with worker protection measures that had been compromised by the pressure to produce, both resulting in mass casualties that were absorbed, reported minimally, and followed by a resumption of production. And of course, no one learned a fucking thing from the explosions. They just tried to sweep it under the rug and push on. They had a war to fight after all. There was men to kill and those big guns needed to be fed. So they pushed production onward. Now was not the time to

Aftermath, Ruins, And The Safety Question

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stop. However, the armistice was signed on november eleventh, nineteen eighteen, five months after the explosions. With the war over, the split rock plant closed not long after due to it no longer being needed. The old quarry fell silent once more and was left to rot again. Eventually, new safety regulations were put into place. Tighter regulations on dealing with chemical reactions were put into effect. New safety protocols to protect the workers were enacted. The loophole that allowed them to get away without any sprinklers was closed. And now with all the advancements today, things are much safer than they have ever been. But are they really that much safer? Accidents still happen, complacency still sets in, and safety regulations are allowed to go lax. All in the name of somebody's profit. Sure, we tell ourselves that it's all in the name of something bigger than ourselves. So we feel like it's important, but is it really? Is your life worth risking for someone else's gain? Anyways, let me get off my little soapbox there. A memorial for the dead was placed in Oakwood Cemetery in Syracuse, where most of the dead, including the unidentified fifteen, are buried. The quarry itself is still there. Obviously, it's really just a hole carved into the hills. It saw some use until the nineteen eighties as a maintenance depot and parking facility for the Department of Transportation, but once they pulled out in the nineteen eighties, it was left to be reclaimed by nature. Some of the original buildings, like the Stone Crusher, are still there, lying in ruins, along with tunnels dug into the hills and limestone caves dotting the area. And it's now a part of the Edgecliff Park and has become a popular spot to go hiking, or really, just to go dig through a historical site. You know, playing amateur archaeologist or whatever. Which sounds like a hell of a good time actually. Anyways, that was the Split Rock Quarry Explosion.

Wrap Up And Ways To Connect

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Thanks for listening. If you like the show, please consider leaving a rating or review on your Apple Choice. And you can reach out to the show at histories of Disaster at Gmail dot com with questions, comments, or suggestions. As well as following the show on social media like Facebook, Instagram, TikTok, YouTube, whatever you know the deal. Promise one day I'm gonna get better with it. Almost done with class. And share the episode. Your friends will love it. Just because penguins do like to collect rocks, don't force your little penguins to work on a quarry. It's not a very nice thing to do. So chase that dream, as long as you're not enslaving penguins. Live for today, because tomorrow is never guaranteed. Thanks and goodbye.