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.

Vice President JD Vance visited East Palestine on Monday to see what still needs to be done and how to avoid another disaster.