NEW DELHI – A power grid failure blacked out northern India for hours Monday, halting trains, forcing hospitals and airports onto backup power and providing a dark, sweltering reminder of the nation's inability to meet its energy needs as it strives to be an economic power.

While the midsummer outage was unique in its reach – it hit 370 million people, more than the population of the United States and Canada combined – its impact was softened by Indians' familiarity with almost daily blackouts of varying duration. Hospitals and major businesses have backup generators that seamlessly kick in during power cuts, and upscale homes are hooked to backup systems powered by truck batteries.

Nonetheless, some small businesses were forced to shut for the day. Buildings were without water because the pumps weren't working, and the vaunted New Delhi Metro, with 1.8 million daily riders, was paralyzed during the morning commute.