A power cut at Heathrow terminal five has caused large queues and led to scenes of confusion, with some travellers being told their luggage would not be leaving London with them.
Passengers had their journeys severely disrupted after a power supply issue led to confusion over flight times, departure gates and whether suitcases would make it on to their correct planes.
Many tweeted pictures of the scene, others posting comments about the "chaos".
Local train and Tube services were also disrupted, with the Piccadilly Line, one of London Underground's busiest routes, experiencing severe delays between Heathrow tube stations for two-and-a-half hours during the Tuesday morning rush-hour, Transport for London confirmed.
A Heathrow spokesperson told The Huffington Post UK: “This morning Terminal 5 suffered a loss of power due to an issue with our supplier.
"Power has now been restored, however the baggage system was impacted for a number of hours.
"We apologise to passengers affected and we are working hard to ensure that they are reunited with their bags as quickly as possible. Flights are continuing to operate as normal.”