Reports say that the collapse was triggered by four states withdrawing power from the northern grid at the same time. This led to a transmission failure at Agra.
Jammu and Kashmir, Himachal Pradesh, Punjab, Chandigarh, Haryana, Delhi, Uttarakhand, Uttar Pradesh, Rajasthan, West Bengal, Bihar, Jharkhand, Odisha, Sikkim, Chhattisgarh, Assam, Arunachal Pradesh, Nagaland, Mizoram, Manipur, Meghalaya and Tripura were consequently affected by the world's biggest-ever blackout.
Nearly 500 trains stopped running all of a sudden. Vehicular movement was also affected. Traffic came to a grinding halt in many cities across north and east India.
Seeing how grave the situation was, West Bengal Chief Minister Mamata Banerjee even declared a holiday in her state to enable professionals and workers to reach their homes as soon as possible.
Due to the grid failure, hundreds of miners were trapped underground in Asansol and Sodedur. The mines are operated by the Eastern Coalfields Ltd.
Meanwhile, thousands of patients in hospitals suffered because doctors could not perform urgent surgeries in the absence of electricity.