On a day that over 600 million people were grappling with the electricity crises, the government moved Sushil Kumar Shinde from the Power Ministry to the more sensitive Home Ministry.
The power failure also left around 200 miners trapped in a mine in West Bengal's Burdwan district. The miners of Eastern Coalfields Ltd (ECL) were rescued after emergency power supply was arranged.
Over 300 trains were also left stranded mid journey for hours, affecting around 3,00,000 rail passengers.
The power was restored to a large extent at around 7.30 PM after more than six hours. The blackout on July 30 had lasted from 2.30 AM to late morning.
"The grid incident occurred at 1PM, affecting the northern, eastern and north-eastern grids. The system is under restoration," said the official website of the Eastern Grid, among the systems managed by the state-run Power System Operation.
The states affected on July 31 were Jammu and Kashmir, Himachal Pradesh, Punjab, Haryana, Delhi, Rajasthan, Uttar Pradesh, Bihar, West Bengal, Odisha, Jharkhand, Sikkim, Assam, Meghalaya, Tripura, Nagaland, Manipur, Mizoram and Arunachal Pradesh. These states account for half of India's 1.2 billion population.
Shinde, who had constituted a committee to probe the failure on July 30, attributed the collapse to overdrawing of power by four states - Uttar Pradesh, Punjab, Rajasthan and Haryana. However, all four states denied the charge.
The capital's popular Delhi Metro, which caters to 1.8 million passengers on a weekday, suspended service on all its six lines due to the power trip, inconveniencing thousands of passengers. Metro services were resumed fully at 5.30 PM.
There was chaos on the streets of the national capital as Delhi Metro commuters spilled on to the streets to look for alternative transport. With traffic-lights on the blink, over 4,000 traffic policemen manned the intersections amid the intermittent rain.
Hospitals in Delhi were unaffected by the crises due to their power back-ups, as was Delhi's international airport. Flight operations remained normal.
Speaking to reporters at around 4 PM, Chairman and Managing Director of state-run Power Grid Corp of India, RN Nayak, said that the failure was due to overdrawal of power by some states and that a full inquiry would reveal the nature of the problem. He added that every effort was being made restore supplies fully by 7PM or 7.30 PM, but normalcy would return only by midnight.
He said that the excess power drawn by the states had a cascading effect on the other states.
The Power Grid Corporation of India, which controls the country's transmission network, said that the situation across the country would be normal by midnight.
At present, the Northern Grid is getting power from Gwalior and Agra substations as well as from three hydel projects - Tehri and Vishnu Prayag in Uttarakhand and Nathpa Jhakri plant in Himachal Pradesh - he said.
According to Nayak, the demand across the three regions is around 55,000MW.
Except for a few areas in Kolkata and Delhi, and Narora (Uttar Pradesh), all three regions were affected, he said.
At the time of failure, Northern Grid's demand was about 32,400MW, Eastern Grid (12,000MW) and North Eastern Grid (1,100MW), respectively.
Bihar Chief Minister Nitish Kumar said that the central government should ensure that no state draws electricity beyond its sanctioned load. "For this, they will have to develop and strengthen the infrastructure," he stated.
The US had faced a major power blackout in early July following a storm, that left large parts of the the East Coast without power for a few days and affected two million people.