On Feb. 3, 2023, a Norfolk Southern freight train carrying hazardous materials derailed after a railcar's wheel bearing overheated, causing a fire. Three days later, officials conducted a "controlled release" of several tank cars that were filled with vinyl chloride, a toxic and flammable gas that can cause certain cancers, to prevent an explosion.

On the evening of Friday, February 3, 2023, 38 of 149 cars of a Norfolk Southern Railway freight train derailed in East Palestine, Ohio. Five of the derailed cars were carrying vinyl chloride, a hazardous material that built up pressure in the resulting fires,