London’s Heathrow Airport closed Friday due to “significant power outage” from nearby fire

London’s Heathrow Airport — one of the world’s busiest — announced that it would remain closed for all of Friday due to a “significant power outage” caused by a fire at a nearby substation.

“Due to a fire at an electrical substation supplying the airport, Heathrow is experiencing a significant power outage,” a post on the airport’s X account said. “To maintain the safety of our passengers and colleagues, Heathrow will be closed until (11:59 p.m. Friday local time). Passengers are advised not to travel to the airport.”

Tracking services showed flights being diverted to London’s Gatwick Airport, Charles de Gaulle Airport in Paris and Ireland’s Shannon Airport.

The FlightRadar24 live tracking website showed at least 1,350 flights into and out of Heathrow were affected. According to the online service, the top route to and from Heathrow is the connection with New York’s JFK International Airport, with 146 flights every week.

The impact was likely to last several days as passengers attempted to make alternate plans. 

Aviation consultant John Strickland told The Associated Press that it would take several days for air travel around the globe to recover from the closure at Heathrow, which is one of the busiest connection hubs in the world.

“We’re talking about several days’ worth of disruption to get the planes recovered and start using them again to move planned and disrupted passengers,” he said, comparing the outage to “a contained version of 9/11 or, to an extent, the Icelandic volcanic eruption” in 2010 that shutdown European airspace.

“Heathrow being such a busy airport and full, there’s no kind of wriggle room for getting out of these kind of things,” Strickland told the AP.

Britain’s National Rail service cancelled services to and from Heathrow for the day.

The London Fire Brigade said 10 fire engines and around 70 firefighters were sent to tackle the blaze at a substation near the airport in the west London town of Hayes. It started late Thursday night, and by about 8 a.m. local time, the brigade said it was “under control, but we will remain on scene throughout the day.”

The fire was “producing a significant amount of smoke. Please keep your windows and doors closed and avoid the area where possible,” the brigade urged area residents.    

The power outage affected “a large number of homes and local businesses, and we are working closely with our partners to minimise disruption,” Assistant Commissioner Pat Goulbourne said in a statement, adding that firefighters had led 29 people to safety from nearby properties, and around 150 people were evacuated.

Scottish and Southern Electricity Networks said in a post on X that the power outage affected more than 16,300 homes.

Authorities said it wasn’t clear what had sparked the blaze at the substation, but U.K. Secretary of State for Energy and Climate Change Ed Miliband told LBC Radio there was no immediate suggestion of foul play.

The latest numbers from travel data provider OAG Aviation show Heathrow is the fifth busiest airport in the world. It is Britain’s busiest.

The Associated Press contributed to this report.