A massive grid failure has left more than half of India's population — over 600 million people — without power. This is the second large-scale outage to hit the country in as many days.

Tuesday's blackout hit more than 12 states in the country's north and east, including major cities like New Delhi and Kolkata. It brought rail service to a halt and knocked out traffic signals in the capital.

Hundreds of miners also were trapped in the eastern state of West Bengal when grid failure cut electricity in their underground mines.

The chairman of India's power grid company said he hoped to have power restored Tuesday evening .

Power companies had restored service to northern India late Monday after an outage that affected more than 300 million people in seven states, but the grid collapsed again on Tuesday .

Limited power failures are common in India, but analysts say such large-scale outages highlight the weaknesses in the country's infrastructure as India strives to become an economic superpower.

India relies heavily on coal to produce electricity for its more than 1.2 billion people.