Hurricane Irene could end up shutting down New York City for days.

The city's subway and mass transit system closed at noon on Saturday, and ahead of Irene's arrival Mayor Michael Bloomberg said subways weren't likely to be reopened on Monday. Without a functioning subway system, New York would remain at a virtually standstill.

Bloomberg also issued a mandatory evacuation of all New Yorkers living in Zone A areas, including Brooklyn's Coney Island and Manhattan Beach, Far Rockaway in Queens, low-lying areas on Staten Island, and Manhattan's Battery Park City by 5 p.m. Saturday. Some 350,000 New Yorkers have been ordered to evacuate, and Bloomberg said about 14,000 have sought shelter in emergency housing provided by the city.

Nearly, 5,000 flights have been canceled in anticipation for Irene's arrival.

Check out the below pictures of people fleeing their low-lying flood-prone areas to safety.

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