A failure in the computer network at Heathrow airport's terminal 3 yesterday disrupted flights for thousands of passengers.
Two flights were cancelled, dozens of others were delayed, and thousands of bags were not loaded on to planes after the glitch hit the terminal, which mainly serves long-haul flights.
Around 3,000 passengers flew from the terminal unaware that their bags were not on their flight. The airport was today trying to reunite those passengers with their luggage.The two cancelled flights were operated by Jet Airways, the Indian airline, and Thai Airways.
A Heathrow airport source said: "There are two networks at terminal 3, one a legacy network the other a shiny new one.
"We think that a device was plugged into both networks and started to get some feedback and conflict with both of them. We have identified three potential devices, electrical components such as a switch."
The glitch brought down both networks at the terminal yesterday afternoon, covering flight information screens, security cameras and check-in systems.
Around 6,000 passengers were locked out of the terminal due to fears over safety, partly because the security cameras were down, but also because of the backlog of passengers unable to check in.
The IT engineers were able to isolate the potentially faulty components and largely restore the networks later in the afternoon.
The airport said in an update this morning, "A computer problem that affected terminal 3's baggage system last night has now been resolved, and the terminal is operating normally. We are sorry for the inconvenience caused to passengers."