NEW DELHI — Northern India's power grid crashed Monday, halting hundreds of trains, forcing hospitals and airports to use backup generators and leaving 370 million people — more than the population of the United States and Canada combined — sweltering in the summer heat.

The blackout, the worst to hit India in a decade, highlighted the nation's inability to feed a growing hunger for energy as it strives to become a regional economic power.

Some small businesses were forced to shut for the day. Buildings were without water because the pumps weren't working. Muslim families were forced to eat their pre-dawn meals by candlelight before beginning their daytime Ramadan fast. "It was really difficult," said farmer Mohammed Zaman.