‘Superstorm’ blaze: At least 50 homes destroyed in massive fire in Queens, N.Y.

Hurricane Sandy may have left the region, but New Yorkers woke up today to flooding, fires and destruction.

A six-alarm fire in Breezy Point, Queens—a coastal area under mandatory evacuation order ahead of the storm—has destroyed about 50 to 100 buildings. Nearly 200 firefighters have responded to the massive blaze, a challenge to battle because first responders had to wade through chest-high water to reach the homes.

Firefighters told ABC News they rescued 25 people gathered in one apartment there. So far, no casualties from the fire have been reported.

[Updated photos: Massive fire in flooded Queens]

The New York Fire Department kept New Yorkers informed on Twitter as Sandy tore through the city Monday night, causing several small fires as well as the total collapse of the facade of an apartment building in the tony Manhattan neighborhood of Chelsea.

At one point, the fire department implored people on Twitter not to use the social media site in place of 911, as some were asking for emergency assistance by tweeting. "PLEASE NOTE: *Do not* tweet emergency calls. Please call 911. If it is not an emergency, please call 311. #NYC #Sandy," the FDNY tweeted. The city's 911 system was overloaded for much of the evening and night.

At least two homes were also destroyed in a fire in Old Saybrook, Conn., an area also under evacuation order.

Many New Yorkers saw blue and green sparks cross the sky as transformers exploded at a ConEd plant in Manhattan around 8:30 p.m., plunging much of the island into darkness. ConEd's John Miksad told Bloomberg that the explosion and other storm-related damage have caused "the largest storm-related outage in our history."

Nearly 700,000 people in New York City are without power, and there's no word yet on when their electricity will be restored. Flooding has also severely damaged the city's mass transit system, with MTA leaders reserving judgment on when subway service will be restored.