"Power generation tends to drive all the response and recovery activities," said FEMA chief Craig Fugate on Tuesday, adding that his agency had deployed hundreds of generators around the East Coast before the storm.

In New York, Democratic Sen. Charles Schumer said FEMA was now sending additional generators to the state and city, which saw a spectacular explosion at a substation near the East River during the storm.

Any mistakes now by FEMA could remind the public of past failures and hurt President Barack Obama just a week before voters head to the polls.