US-based airlines were forced to cancel over 7,000 scheduled flights in to and out of the Northeast corridor on Sunday.

Flight cancellations began in the region from Washington D.C. to Boston as early as Sunday evening as states and municipalities began to make preparations for what some are predicting will be the largest storm to ever make landfall in the United States.

Flooding is expected, along with hurricane force winds. In some areas further north snow will also be a factor. In New York City flights were cancelled according to the timing imposed by the city’s shutting down of mass transportation at 7pm on Sunday. By 9pm all flights in and out of NY were cancelled. Fees for changing travel plans due to the cancellations were waived by the airlines.

U.S. Airways says it will be forced to cancel at least 2,000 flights, from Sunday at 7pm until sometime on Tuesday. The spokesman added that delays could be extended depending on the duration and strength of the storm and the damage it might cause. Planes on the ground will be repositioned away from the Hurricane’s path to avoid damage to them, which will cause additional delays.

George Hamlin, transportation consultant predicted that Sandy will cost the airline industry hundreds of millions of dollars. Not only will the airlines lose flight revenue, but they will probably have to pay their crews extra if they are stranded away from their home bases.