United Airlines passengers at airports across the country took to Twitter Tuesday morning to complain about problems printing boarding passes and luggage tags.
At 8:20 a.m. United Airlines reported intermittent nationwide problems with their ticketing system, Laura Coale with Denver International Airport confirmed.
Agents had to hand-write tickets and lines built up at the ticket counters, Coale said.
"@united some people can print boarding passes, no baggage tickets printing. We're going to miss our flight," @mirthfulabode tweeted Tuesday morning.
"@united all your systems are down at sfo and ur (sic) reps are HANDWRITING TICKETS!!!" @tawny_mmkay tweeted.
United responded, "We're aware of the problem. We're working to fix it as quickly as possible."
The system was reportedly back online at about 9:45 a.m. Delays at DIA were minimal, Coale said, and operations were expected to return to normal quickly.
Some disgruntled travelers said the delays were still a problem at 10:45 a.m.
"Delays are absolutely nuts. Already missed my 10:09 departure," @jessewilkins tweeted.