Operating on backup generators since 'superstorm' Sandy knocked out power, New York's Bellevue Hospital Center was forced to evacuate about 500 patients on Wednesday.
Several other area hospitals had been contacted about the evacuation and were coordinating efforts to provide care for evacuees.
Here in Manhattan's Kips Bay neighbourhood, ambulances wait to ferry patients to other facilities, including the Mount Sinai Hospital and St. Luke's Roosevelt Hospital Center.
A handful of other New York hospitals had already been evacuated due to record flooding in low lying areas.
New York University's medical centre evacuated all 215 of its patients, including critically ill infants, when its backup generator failed after flooding in its basement.
The Manhattan Veterans Affairs Hospital and the New York Downtown Hospital both preemptively evacuated patients ahead of the storm surge.
National Guard troops were on hand to help in the Bellevue evacuation.
Sandy slammed into the eastern seaboard with Hurricane-force winds on Monday evening.
It's the largest storm on record to hit the United States.
