Tens of thousands of Delta passengers around the world were grounded Monday after a power outage at its Atlanta headquarters caused a global system-wide computer failure.
Check-in systems, airport screens and even the airline's website and smartphone apps were affected by the problem, which began at 2:38 a.m. ET and lasted more than six hours.
The airline suspended departures, with airport agents are writing out boarding passes by hand. "Our systems are down everywhere," it told customers on Twitter.
The global outage ended at about 8:30 a.m. ET, but customers were warned that major delays and cancellations would continue.
Thousands of customers spent the night on airport floors.