JUDY WOODRUFF: And to India, where an area with a population of 700 million, almost one-tenth of the population of the entire world, lost power Tuesday, when three of the country's regional electricity grids failed.
It was by far the largest blackout in human history. And it came as millions of Indians faced summer temperatures well into the 90s.
NIYAZ AHMAD, India (through translator): The northern grid failure has created many difficulties for people. This is summertime and hospitals, air conditioning and factories are not able to function. People are facing many problems due to this failure.
JUDY WOODRUFF: The outage encompassed 20 of India's 28 states, a vast region that stretches 1,900 miles east to west. It's home to roughly half of India's entire population. In city after city, major transit systems were shut down. And passengers were left stranded as hundreds of trains across the country sat motionless on the tracks.
MAN (through translator): I was going to board a train to Delhi, but we just found out a while ago that the trains are not functioning due to a grid failure. We have been here since 1:00 p.m.
JUDY WOODRUFF: In the capital, New Delhi, police directed traffic after signals went dark, causing massive jams and confusion. The power began to return within hours. But all of this came on the heels of yesterday's outrage, which left 370 million Indians in the dark for most of the day.
Officials blamed growing demand for air conditioning and less rainfall than usual. This meant lower water flows for hydroelectric dams. They also pointed to large-scale illegal siphoning of power and regional governments taking more than their share.
MAN: Northern and eastern, both the grids have failed, and at the moment, the reason is by overdrawing the power by many states.
JUDY WOODRUFF: It was unclear exactly how many Indians actually lost power. That's partly because one-third of the country's households have no electricity, according to Indian census data.
And gas-powered generators are widespread in a country where smaller-scale blackouts are common. Even so, two major outages in 48 hours underscore the problem. India's growing demand for power has outstripped its power system.
G.K. SEHGAL, India: One grid failure, and the entire country of north India was at a standstill. This is a system failure, a systemic failure.
JUDY WOODRUFF: And the problem is likely to persist. The Indian government recently scaled back plans to spend $1 trillion to rebuild infrastructure over the next five years.