Tens of thousands of Delta Airlines passengers around the world were stranded on Monday by a computer outage that the company said had grounded all its flights. It blamed a power failure at its hub in Atlanta. "Delta has experienced a computer outage that has affected flights scheduled for this morning," the company said in a statement. "Flights awaiting departure are currently delayed. Flights enroute are operating normally," the Atlanta, Georgia-based US airline said. Delta urged travelers to check the status of their flights "while the issue is being addressed." Delta said in a later statement the breakdown was caused by a power outage in Atlanta that began at around 2:30 am (0830 GMT). It said large-scale cancellations were expected Monday. On Twitter, Delta representatives urged patience and apologized as they dealt with a flood of messages from concerned passengers. "All our flights are grounded due to the outage," read one tweet. "We're experiencing a systemwide issue," read another. Lines of passengers were backing up at Delta ticket counters at US airports. At Los Angeles, passengers on a flight to New York had to get off their plane and return to the terminal, NBC News reported, while some people slept near departure gates at Las Vegas. A vast number of flight delays normally creates a cascading problem that affects airline traffic for days. Computer outages halting flights are not uncommon. In May a glitch affecting Sweden's civil aviation authority radar site disrupted air traffic throughout that country and grounded flights to and from Stockholm for several hours. In March, a computer system malfunction forced Japan's All Nippon Airways to cancel more than 100 domestic flights, affecting some 16,000 travelers. And in mid-August 2015 a computer problem at a regional air traffic control center delayed hundreds of flights at busy US east coast airports — including those in the Washington and New York areas — for several hours. A rival US airline, United, suffered computer glitches in May and July 2015 that temporarily grounded hundreds of flights and backed up thousands of passengers.
