Sandy shuts down Northeast air travel

Superstorm Sandy grounded more than 18,000 flights across the Northeast and the globe, and it will take days before travel gets back to normal. According to the flight-tracking service FlightAware, more than 7,000 flights were canceled on Tuesday alone.

Authorities closed the three big New York airports because of the storm. New York has the nation's busiest airspace, so cancellations there can dramatically affect travel in other cities. (AP)