Atlantic City, NJ -
Air Traffic from parts of the southeast U.S. and some other areas into the Northeast have suffered significant delays and cancellations due to a fire at an FAA operating center, the William J. Hughes Technical Center, which handles traffic flow systems. Those systems allow the FAA to issue "ground stops" and "ground delays" to specific airports when destination airports are too busy and other reasons.
Normally the traffic flow system is an automated process allowing controllers to issue such orders with just a few clicks, but with the system down, controllers have had to call airport towers and airlines directly, making the task much more time consuming. This had resulted in airports like Orlando and Miami to have numerous delayed and cancelled flights to airports in the northeast such as JFK, Newark, and Boston.
The fire interrupted the system's electrical power and controllers were slow to switch to a manual backup process as described above.
JetBlue's COO tweeted that 66 flights from the southeast into the northeast have already been cancelled. Adding to problems, strong storms crossed the New York City area furthering causing more delays.