The departures of all United Airlines were halted system-wide for two hours due to a computer malfunction. It is said that the problem was computer outage which lasted from 6 a.m. to 8 a.m. PDT, when the departures were able to resume. O’Hare, Dulles and airports in Denver, Los Angeles and San Francisco are the hubs of United Airlines and all United flights across its system had been grounded because of the computer hangups. Inbound and outbound flights of United Airlines at O’Hare International Airport were delayed between one and two hours. However, United flights at Washington Dulles International Airport did not affect departures on any other airlines. At San Francisco International Airport, a dozen United flights had been affected and most delays averaged 20 to 30 minutes. Transportation officials say delays were shorter at Washington, Denver, Los Angeles and San Francisco. The cause of the problem is not yet known. Image Source: CNN