Delta Air Lines said it canceled nearly 500 flights Tuesday as it tries to get operations back to normal following a computer systems failure Monday.
The company blamed the outage on a loss of power at its hub in Atlanta, saying some of its critical systems failed to switch over to a backup that would have kept them running.
Without a functioning computer network, Delta grounded all flights for hours Monday, eventually canceling about 1,000 flights across the United States and beyond. Thousands more flights were delayed.
Flights resumed by Monday night, but a Delta official said Tuesday the airline was "still operating in recovery mode."
Industry experts have begun linking airline computer system failures to corporate mergers that require integrating older computer systems from rival companies into a single, expanded system operated by the new corporation.
Analysts say such outages in older systems also are becoming more common as carriers continue to automate flight-related services and a host of behind-the-scenes activities involving everything from worker schedules to electronic arrival and departure displays.
Last month, Southwest Airlines issued formal apologies and a host of rebates to passengers affected by 2,300 cancellations and 8,000 delayed flights when its computer systems, already taxed by an airline merger in 2010, collapsed. The company has since begun investing millions of dollars into new technology.
United Airlines had similar problems last year.