At around 5:30 a.m. on July 14, 2025, a freight train carrying diesel derailed near Tiruvallur station in Tamil Nadu. A spark from the overhead electrical lines likely ignited diesel leaking from one of the wagons. The fire spread across 18 wagons and generated thick black smoke, alarming locals and prompting the swift evacuation of approximately 500 residents from nearby areas :contentReference.
Nearly 17 fire trucks, National Disaster Response Force teams, and Coast Guard units worked tirelessly for about 10 hours to extinguish the fire. Thankfully, no casualties were reported. Emergency protocols included cutting off overhead power and shutting down train services on the busy Chennai–Arakkonam route. Around 12 express trains were canceled or rerouted, and passenger buses were arranged to handle the disruption :contentReference.
Authorities suspect a crack in the tracks may have contributed to the derailment, while railway investigators are also exploring mechanical defects and the possibility of a malfunctioning axle. A high-level inquiry is ongoing. The fire led to an estimated ₹12 crore worth of diesel being lost and caused widespread delays. Three of the four rail lines returned to service by late evening, and residents who were evacuated have since returned home :contentReference.
Officials advise rail commuters along the Chennai–Arakkonam line to check rail updates and use alternative transport if needed. They also urged the public to stay clear of the fire site and follow railway safety alerts. Investigative findings are expected to determine the exact cause and anything that can prevent future incidents :contentReference.