New York began to mop up and pump out the water after massive flooding from Hurricane Sandy, which engulfed much of the city and its outer boroughs when it hit on Monday.

According to Consolidated Edison Co. spokesman Chris Olert, more than 656,000 homes and businesses experienced power outages stemmed from Hurricane Sandy, which also killed at least 18 people in New York City. ConEd said 288,000 customers in Manhattan, 118,000 in Staten Island, 45,000 in the Bronx and 205,000 in Brooklyn and Queens lost power.

The storm caused flooding to most of New York City's Metropolitan Transit Authority, or MTA, chairman Joseph Lhota said, calling the aftermath of the storm the worst disaster in the history of the MTA. Seven East River subway tunnels, two Long Island Rail Road tubes linking Manhattan with Queens and two automotive tunnels were flooded, along with one subway bridge, three train yards and six bus depots. 

Many people posted photos of the mass flooding of the NYC transit system, which appeared to be almost half under water. A video released by the MTA posted by showed MTA workers inundated in water in the entrances to the subway.

New York City Mayor Michael Bloomberg said subway service may not be restored for up to five days.

“We’re on the road to recovery,” Bloomberg said. “We’ll try to take this and use it as a lesson.”

The New York City bus system operating on a Saturday schedule will be free of charge to provide transportation for the entire city. Mayor Bloomberg said yellow taxis will be allowed to pick up multiple passengers until subway service is restored.

The Wall Street Journal reported the effects of Hurricane Sandy "will be felt for months or even years."