Molten Sulfur Train Derailment in Rural Kentucky Triggers Shelter-in-Place—and a Test of Small-Town Hazmat Response

Before dawn on the Tuesday after Christmas, as an arctic blast pushed temperatures below freezing in southern Kentucky, residents of Trenton woke to an instruction that cut against every winter instinct: stay inside, and turn the heat off.

A CSX freight train derailed along U.S. 41 just west of the tiny Todd County town shortly after 6:15 a.m. on Dec. 30, sending 31 rail cars off the tracks. At least one tank car loaded with molten sulfur ruptured, leaked and caught fire, releasing a low-lying plume of chemical smoke that led local officials to issue a shelter-in-place order for roughly a half-mile radius — a zone that encompassed most of the community’s roughly 330 residents.

Authorities say the incident ended without injuries and with limited environmental effects. The chemical fire was extinguished by late morning, and air monitoring showed gas levels low enough for officials to lift the shelter-in-place around 11 a.m. But for a rural county that relies heavily on volunteers and mutual aid for hazardous-materials response, the derailment underscored how dependent small towns are on outside help and on decisions made by the railroads that run through their backyards.

“We got there pretty quickly, and it was quite a bit more than we expected,” said Chuck Sadler, a volunteer firefighter with the Trenton Fire Department who lives less than a mile from the tracks. “There was some smoke, low-hanging smoke, and did notice like a little irritation to the throat, but nothing severe. And we just got upwind of it and stayed there.”

What happened

The train, operated by CSX Transportation, derailed along the Dixie Bee Line Highway near Trenton Tress Shop Road, about a mile west of downtown and a short drive from the Tennessee border. CSX said 31 cars left the tracks. Local officials initially reported a lower number as they assessed the scene.

One of the derailed tank cars carrying molten sulfur was breached and ignited. Sulfur is shipped in insulated cars at temperatures above its melting point so it remains liquid. When it burns, it can produce sulfur dioxide, a pungent gas that can irritate the eyes, nose, throat and lungs, and under some conditions hydrogen sulfide, which is highly toxic in high concentrations.

Because those gases are heavier than air, they can collect close to the ground, which responders said matched what they saw over the fields west of Trenton.

“It was a visible cloud,” said Todd County Emergency Management Director Ash Groves. “That’s what prompted us to go ahead with the shelter-in-place, to keep folks indoors, windows closed, HVAC systems off until we could get reliable air monitoring on scene.”

Groves said the order covered approximately a half-mile radius around the derailment, including much of the city of Trenton. Residents were told to stay inside and shut off heating and ventilation systems to avoid drawing in fumes — a difficult request as wind chills dipped well below freezing.

To help residents who could not safely remain in unheated homes, officials opened a warming shelter in nearby Guthrie. Fewer than 100 homes fell within the shelter-in-place zone, according to the Trenton Fire Department.

Gov. Andy Beshear amplified the warnings on social media, telling Kentuckians that a train had derailed in Todd County and that local emergency management had ordered Trenton residents to shelter in place. “Please follow local guidance and stay safe,” he wrote, adding that state agencies were monitoring the situation while local officials led the response.

Response and cleanup

Hazardous-materials units from Christian County and the city of Hopkinsville joined Trenton’s volunteers at the scene. CSX deployed its own hazmat specialists and contractors to help contain the leak, fight the fire and begin planning removal of contaminated material.

By late morning, crews had extinguished the fire involving the sulfur car. Groves said air monitoring in and around Trenton showed gas levels had fallen to what officials consider safe for the general public.

“Everything is good now,” he said as the shelter-in-place was lifted, emphasizing that no injuries had been reported among residents, train crew or first responders.

CSX said in a written statement that its crews were working “as safely and quickly as possible” to clean up the derailment. “We appreciate the swift response and coordination of local first responders and emergency management officials,” the company said. “Our primary focus continues to be the health and safety of onsite personnel, the surrounding community and mitigating any potential risk to the environment.”

The railroad advised customers that the incident would cause shipment delays through the region, but said service on the line was restored by the following day. The company said the cause of the derailment remains under investigation.

As of early January, the National Transportation Safety Board had not publicly announced a major investigation focused on the Todd County derailment, suggesting the probe may proceed through routine Federal Railroad Administration channels and internal CSX reviews rather than a full board hearing.

Why it matters for rural communities

The derailment occurred on a key CSX corridor that carries mixed freight between the Midwest and the Southeast. Towns like Trenton, with a 2020 population of 331 and about half a square mile in area, sit directly beside those lines. For many residents, long freight trains and the sound of horns are part of daily life.

What is less visible is the cargo. Molten sulfur, used to make sulfuric acid for fertilizers and petroleum refining and in a range of industrial processes, is one of many hazardous materials that move by rail across the United States. Federal data show that more than 99.99% of hazardous materials shipments by rail reach their destination without a release caused by a train accident, and industry groups note that derailment rates have declined significantly since 2000.

Yet a joint analysis by the Associated Press and the University of Maryland last year found that train derailments releasing at least 1,000 gallons of hazardous materials still occur about once every two months in the U.S. Nearly half of those incidents led to evacuations, and more than a quarter involved fires or explosions, according to that review.

The same analysis reported that only about one in five U.S. fire departments has a dedicated hazmat team. Rural communities like Todd County often depend on neighboring jurisdictions and railroad contractors, which can extend response times if conditions deteriorate quickly.

Todd County Judge-Executive Todd Mansfield, the county’s top elected official, said the outcome in Trenton could have been far worse if weather, wind or timing had been different.

“There was potential for catastrophe,” he said, crediting local volunteers and regional hazmat teams for the lack of injuries. “When you’re a small county and something like this happens on your doorstep, you realize how much you rely on people from outside coming in to help.”

Broader safety questions

The derailment comes nearly three years after a Norfolk Southern freight train derailed in East Palestine, Ohio, releasing hazardous chemicals and leading to a controversial vent-and-burn of vinyl chloride tank cars. In that case, the NTSB later found that a failed wheel bearing caused the derailment and that the decision to intentionally burn the vinyl chloride was unnecessary and based on incomplete and misleading information.

The Ohio crash prompted renewed scrutiny of freight-rail safety, tank-car standards, trackside defect detectors and emergency communications with local responders. Federal officials have called for accelerating the replacement of older tank-car designs and expanding the use of hot-bearing detectors and other technologies intended to spot problems before trains leave the rails.

Questions raised by the Todd County derailment — including what caused it, what type of tank car carried the molten sulfur and how the car performed — could factor into those ongoing debates, even if the incident does not receive the same national attention as East Palestine.

Back to normal, with unease lingering

By midday on Dec. 30 the most visible signs of the emergency had faded. The smoke plume had dissipated, the order to stay indoors was gone and residents were turning their furnaces back on as temperatures remained frigid. Freight trains resumed rolling past the town’s edge.

In official records, the episode is likely to be logged as a minor hazmat release: no deaths, no mass evacuation, no long-term contamination reported. For the people living within that half-mile radius west of U.S. 41, it was a morning when a train they could not see stopped their routines, chilled their homes and briefly brought distant national fears about hazardous cargo to their own front doors.