Several arriving and departing flights between cities across Canada and London's Heathrow Airport were cancelled after an overnight fire caused a power outage and forced the British airport to close Friday, with further flight disruptions expected to last for days.
As of early Friday, Toronto's Pearson airport listed at least five scheduled arriving flights from Heathrow as cancelled, as well as two departing flights. Airports in Vancouver and Montreal also listed multiple cancelled flights.
Those flights were among at least 1,300 to and from Heathrow that were affected by the closure and either diverted or cancelled, according to flight tracking service FlightRadar 24.
We hope to run a full operation tomorrow and will provide further information shortly. Our priority remains the safety of our passengers and those working at the airport. We apologise for the inconvenience caused by this incident. (2/2)
— Heathrow Airport (@HeathrowAirport) March 21, 2025
Heathrow said Thursday that a fire at an electrical substation that supplies power to the airport caused the outage. The London Fire Brigade said the fire was contained but firefighters would remain on scene throughout Friday.
Heathrow had said it didn't know when power would be restored and it expected the disruption to last for days. In an update Friday afternoon, Heathrow said it's now able to restart flights and will prioritize "repatriation and relocation of aircraft." It said the first plane to land since the outage arrived 18 hours after it began.
The airport said it hopes to be fully operational on Saturday.
The closure disrupted the travel plans of about 200,000 people who were expected to travel through the airport on Friday.
Air Canada said Friday that six of its flights on Thursday were diverted mid-air while a seventh was cancelled before departing. Those flights included some from routes through Toronto, Montreal and Calgary.
The airline said early Friday it had cancelled 16 flights in total, including return flights from London. In a later update, Air Canada said it planned to operate its regular schedule of flights starting Friday evening after flights resumed at Heathrow.
Air Canada previously said it rerouted some customers to other European gateways and was helping passengers bound for London to change their travel plans.
WestJet said in a statement that two of its flights between Calgary's international airport and Heathrow were cancelled Thursday and Friday. The airline said no further cancellations were expected, but passengers were advised to check the status of their flight before going to the airport.
Police in London said there was no indication of foul play in the fire, but counterterrorism detectives were leading the investigation that shut down the airport.
A spokesperson for U.K. Prime Minister Keir Starmer said there must be a "rigorous investigation" into how a single fire could shut down Europe's busiest travel hub.
Heathrow chief executive Thomas Woldbye apologized Friday for the daylong closure, but said there was no choice but to shut down the airport for safety reasons.
Heathrow was Europe's busiest airport last year, with 83.6 million passengers travelling through it.
