A massive blackout hit northern and eastern India on Tuesday afternoon, leaving 600 million people without electricity in one of the world's most widespread power failures, according to a report of the Associated Press. The outage came just a day after India's northern power grid collapsed for several hours leaving cities and villages across eight states powerless. Indian officials managed to restore the northern grid by Monday evening, but at 1:05 p.m. Tuesday the grid collapsed again, said Shailendre Dubey, an official at the Uttar Pradesh Power Corp. in India's largest state. About the same time, the eastern grid failed as well, said S.K. Mohanty, a power official in the eastern state of Orissa. The two grids serve about half India's population.