Delta cancelling nearly 250 flights Tuesday morning

The cancellations Tuesday follow about 1,000 cancelled flights Monday and almost 3,000 delayed flights after an outage at its Atlanta headquarters initiated a global meltdown of its booking and communications systems.

Delta's challenge on Tuesday will be to find enough seats on planes during the busy summer vacation season to accommodate the tens of thousands of passengers whose flights were scrubbed.

Instead of being able to stay home, many passengers only learned about the flight problems when they arrived at the airport.

"By the time I showed up at the gate the employees were already disgruntled, and it was really difficult to get anybody to speak to me or get any information," said Ashley Roache, whose flight from Lexington, Kentucky, to New York's LaGuardia Airport was delayed.

Airlines depend on huge, overlapping and complicated systems to operate flights, schedule crews and run ticketing, boarding, airport kiosks, websites and mobile phone apps.

United Airlines suffered a series of massive IT meltdowns after combining its technology systems with those of merger partner Continental Airlines.