Thousands of British Airways passengers were forced to wait in long lines at Heathrow Airport due to a baggage system fault.
Comedian Eddie Izzard, who was was among the passengers caught up in the disruption, posted about the long delays on Twitter.
The problem, which began at around 8am on Thursday, meant the airline had to check in items of luggage manually, which takes longer than the usual automatic procedure.
Terminal 5 was the worst affected, with queues lasting several hours, although the fault also occurred at Terminal 3 and Gatwick Airport.
Cancer nurse Mary Tanay wrote that the chaos caused her to miss her flight and she will be "spending a few hours of my holiday at T5" waiting for the next one.
She added: "What a truly stressful morning for all - staff and passengers alike."
Another passenger, Emily, posted on Twitter that there were lots of staff looking at bags but "no one taking them to planes".
A BA spokesman said: "We are working hard to minimise disruption after a baggage system issue has slowed down customers dropping off their bags. "We apologise for the inconvenience to our customers."