On March 4, 2023, at approximately 2:55 p.m., EST, a Norfolk Southern Railway Company (NS) mixed freight train derailed 28 cars at Milepost 178.7 on the Dayton District near Springfield, Ohio. The train, designated as a Key Train, was traveling at 38 mph when it experienced excessive buffing or slack action caused by the use of dynamic braking combined with its train makeup. No injuries or hazardous material releases occurred, but the derailment blocked State Route 41 and prompted a precautionary shelter-in-place order for a 1,000-foot radius. FRA determined that the primary causes were the use of dynamic braking and the train's configuration, leading to the issuance of Safety Advisories 2023-02 and 2023-03 to address safety concerns regarding train makeup and operations.