returned 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 travellers.
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.