United Airlines was selling some tickets on Thursday for as little as $5 before shutting down bookings on its website.
Some customers were able to buy tickets before the airline stopped accepting orders on the website. Flight searches and bookings were temporarily shut down for all flights. United also halted reservations by phone.
The company says the mistake was due to an error in filing the fares, not a problem with the website. The airline doesn't yet know how many tickets were sold at the unusually low prices. United has not yet decided whether it will honor the tickets.