Mysuru-Darbhanga express collision: How did the passenger train derail?

Tiruvallur (Tamil Nadu), Oct 12 (ANI): In a major mishap, the Mysuru-Darbhanga Express train collided with a goods train near Tamil Nadu’s Chennai on October 11. The incident occurred around 8:30 pm on Chennai-Gudur section between Ponneri and Kavaraippettai railway stations. The incident led to the derailment of at least 12 coaches of train in which as many as 19 passengers sustained injuries. Soon after the mishap, the relief and rescue efforts were underway, and all passengers have been evacuated.