​​​On July 5, 2025, about 2:26 p.m. local time, a southbound Canadian National Railway mixed freight train derailed 22 railcars on the Yazoo Subdivision in Glendora, Mississippi. One of the derailed railcars—loaded with a class 3 hazardous material called benzene—breached and caught fire. About 160 people were evacuated within a 1-mile radius of the accident. No injuries were reported among the public or the train crew.

​​We determined the probable cause of the July 5, 2025, train derailment in Glendora, Mississippi, was wheel climb caused by a track curve deformity that remained unsafe following Canadian National Railway’s attempted repair of the identified defect. Contributing to this accident was Canadian National Railway’s failure to properly remediate the causes of the repeat defects in this curve, as identified by their geotechnical team, or to maintain their continuous welded rail in accordance with the established continuous welded rail plan, which led to the progressive loss of track stability.

​​This accident demonstrates the importance of strict adherence to a comprehensive and well-developed continuous welded rail plan, supported by ongoing auditing and verification under the direct onsite supervision of qualified personnel. The investigation further revealed that inadequate project management allowed a known safety concern to persist without effective corrective action until an accident occurred. Maintaining a complete and current continuous welded rail plan, conducting continuous oversight and auditing, and ensuring qualified project management are essential to identifying and addressing track anomalies before they cause accidents.​