By SAURABH CHATURVEDI and SANTANU CHOUDHURY
NEW DELHI -- Much of India's electricity-supply network collapsed Tuesday in the country's second major outage in two days, affecting more than 680 million people - double the population of the US - and causing business losses estimated to run into the hundreds of millions of dollars.
Thousands of offices and factories had to switch to generators or shut shop, more than 200 trains were brought to a standstill, and hospitals had to ask nurses to manually work critical equipment such as ventilators as 21 provinces experienced a near-total blackout that demonstrated the rickety nature of the infrastructure in Asia's third-largest economy.
Metro rail services in the national capital of New Delhi and its suburbs were halted for several hours as well, a spokesman for the Delhi Metro Rail Corp. said.
At Delhi's international airport, diesel generators kicked in automatically to ensure operations weren't interrupted.
The power outage, the worst in India's history and affecting more than half of its 1.2 billion population, was caused by the failure of power grids at 0730 GMT.
Rabindra Nath Nayak, chairman of the state-run Power Grid Corp. of India, said the company is working to restore normal power supply to all affected regions.
Power Grid operates all five of India's regional grids, or supply networks. It runs more than 100,000 kilometers of electricity-transmission lines.
The northern, eastern and northeastern grids, all of which failed Tuesday, have a combined peak-hour load of about 46,000 megawatts.
On Monday, the northern grid failed, affecting power supply in nine provinces for the worst outage in northern India in 10 years.
Coal-based power plants at NTPC Ltd., India's largest power generator by capacity, stopped operating for several hours Tuesday, Chairman Arup Roy Choudhury said.
The power outage came despite assurances from the power minister about restoring normal electricity supply after Monday's grid failure. It reflects the South Asian nation's inability to supply its homes and businesses with sufficient power - a major concern for local and overseas investors as well as policy makers.
Experts estimate that problems associated with India's creaky infrastructure - including roads and ports - shave off about two percentage points from its gross domestic product growth.
This makes a speedy overhaul of the power infrastructure crucial to boosting economic growth. But efforts by India to build new power plants haven't yet yielded results because of a shortage of coal.
More than half of India's power-generation capacity of 205 gigawatts is coal-based, and Coal India Ltd., the world's biggest coal producer, is unable to produce enough because of delays in getting environmental clearances for mining.
An ambitious program to build nuclear power plants has faced public protests, especially after the nuclear accident in Fukushima, Japan, last year.
Government giveaways in the form of free electricity to farmers and a reluctance among politicians to raise power charges to sufficiently cover costs have drained cash reserves from the largely state-run electricity-distribution companies, leaving them with mounting debt.
India aims to expand its power-generation capacity by 44% over the next five years. In June, power generation fell short by 5.8% of the peak-hour demand of 128 gigawatts, according to government data.
The government has announced the appointment of a three-member panel to investigate the cause of Monday's power failure in northern India. The committee will submit its report in two weeks.
The committee is made up of Arvinder Singh Bakshi, chairman of the Central Electricity Authority, India's power-sector monitoring agency; Power Grid's Mr. Nayak; and S. K. Soonee, chief executive of the state-run Power System Operation Corp.
Chandrajit Banerjee, director general of the Confederation of Indian Industry lobby group, described the two outages as a "telling commentary on the situation of the power sector in the country."
He said businesses incurred hundreds of millions of dollars in losses Tuesday, "which pales into insignificance when compared to the difficulty that the people of the country have had to face."
Mr. Banerjee said the grid failures on two consecutive days "have created a huge dent in the country's reputation."
The exact reasons for Tuesday's power failure weren't immediately known, but Power Grid's Mr. Nayak said tripping at several inter-connectivity points of the [northern] grid could have had a cascading effect.
He added: Even before we could figure out the reason for [Monday's] failure, we had more grid failures [Tuesday].
By 1400 GMT, up to 80% of the power supply had been restored in northern India and up to 45% in eastern India, a spokesman for Power Grid said. In northeastern India, full power supply has resumed.
We are on track to [restoring supply] fully to all the regions as soon as possible, the spokesman said.
This will come as a huge relief, with the effects of Tuesday's outage spreading to mines, hospitals and even crematoriums.
About 200 miners were stranded in an underground mine in eastern India as their elevators were stuck due to the power disruption. All the miners were later safely rescued, said Niladri Roy, general manager of Eastern Coalfields Ltd., a unit of Coal India Ltd. - the world's largest producer of the fuel.
At a coal mine run by Bharat Coking Coal Ltd., another unit of Coal India, about 70 miners were trapped, of which about 20 were rescued by evening, a senior company executive said. Later, the company said the remaining miners had been rescued.
At Nigambodh Ghat, a crematorium in New Delhi, three bodies were cremated using wood after the electricity failed, an official said.
The All India Institute of Medical Sciences, one of Delhi's main state-run hospitals, ran its diesel generators for almost two hours until power supply resumed, spokesman Y.K. Gupta said.
Another hospital, Guru Teg Bahadur Hospital, was worse off: There has been no electricity for the last 11 hours, a duty officer at the hospital said. Only emergency operations can be performed.
A spokeswoman for GAIL (India) Ltd., the country's largest gas distributor by sales, said power stations drew less natural gas Tuesday.
Earlier in the day, Power Minister Sushilkumar Shinde said efforts are continuing to resume supply at the earliest, especially to essential services.
Later, the government announced that Mr. Shinde will take over as the next home minister of India. The power portfolio has been given as an additional charge to Corporate Affairs Minister Veerappa Moily.
The moves aren't linked to the power failure but part of a reshuffling of ministers to allow Home Minister P. Chidambaram to take over the finance portfolio.
Dow Jones Newswires