About 60 percent of Delta's planes use the Atlanta airport on an average day, and the airline says it's still getting planes and crews into position to resume their normal flight schedule.
The storm ravaged much of the city on Wednesday, dumping several inches of rain and leaving behind damaged property and downed trees, according to local media reports.
Delta COO Gil West said in a statement "Wednesday's severe weather was unprecedented for Atlanta... halting much of the day's operation, prompting delays and cancellations".
Passengers who tried to check in to Delta flights Friday reported long lines snaking through the terminal at RDU and some who did not have canceled flights were not able to get to their gates on time because they couldn't check their bags.
The airline extended a travel waiver to help customers change flights without fees if their travel plans are flexible, according to a statement posted on the Atlanta-based company's website on Saturday.
Spring-breakers packing planes compounded an already difficult situation, making it hard for delayed travelers to find available seats and causing a pileup in airports and telephone queues.
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Tusk said progress will be determined by the European Council and that he hopes that could be achieved "in the autumn". It had called for simultaneous talks on exit terms and future trade ties.
More than 700 boxes of pie were delivered to passengers stranded in Georgia, Tennessee, Louisiana, Ohio, Kentucky, and other airports in the Southeast.
Spokesman Michael Thomas told CNN cancellations scheduled for Monday were down to single-digit status.
The flight delays mean long lines to nowhere and sitting in small airplane seats while waiting for a pilot who probably won't ever arrive, which sounds like the flawless layout for hell if the high temperatures ever get too pesky. Rebooked again, her 1:30 p.m. departure on Friday was also canceled for lack of a flight attendant.
Crystal and Wayne Curry described what can only be called a travel nightmare. Delta rescheduled them on a flight for Saturday, but then that flight was canceled. So the Currys chose to rent a vehicle and drive to NY to fly home on another airline Saturday.
For more information on the cancellations and delays, visit here.
"I would have to think that the value of all of the free publicity greatly exceeds the cost of the pizzas, " he said.