Heathrow Airport closed: More than 1,000 flights disrupted due to nearby fire

No flights will arrive or depart at London Heathrow Airport (LHR) after the U.K. hub was forced to close following a fire at a nearby electrical substation.

The airport will be closed on Friday until at least midnight while power is restored and contingency plans are implemented.

“Heathrow is experiencing a significant power outage across the airport due to a large fire at a nearby electrical substation,” said a Heathrow spokesperson. “Whilst fire crews are responding to the incident, we do not have clarity on when power may be reliably restored.”

“To maintain the safety of our passengers and colleagues, we have no choice but to close Heathrow until 23h59 on 21 March 2025.” the spokesperson added.

Significant disruption

Heathrow said they expect “significant disruption” over the coming days and that passengers should avoid traveling to the airport “under any circumstances” until the airport officially reopens.

Heathrow was the fifth busiest airport in the world as of March 2025, per OAG, servicing 4,296,701 seats.

The hub was due to see over 1,330 scheduled flights on Friday, according to data from aviation analytics firm Cirium. Up to 291,000 passengers could be affected, and the knock-on scheduling effects over the weekend are likely significant.

It is unclear how many of the scheduled flight operations will be canceled and how many may be diverted to nearby airports. As of 8:10 a.m. (GMT), at least seven flights scheduled to land at LHR had been diverted to London Gatwick Airport (LGW).

“We are aware of the situation at Heathrow Airport today and we are supporting by accepting diverted flights as required,” a London Gatwick spokesperson told TPG. “Flights are operating from London Gatwick as normal today.”

London Stansted told TPG that it had the capacity to receive a small number of diverted flights today but had “not received any requests” from LHR. At the time of writing, Luton Airport had also not received any requests for help.

One passenger due to fly from LHR to Hong Kong today, Amanda Schuman told TPG that communication from LHR and their carrier, Thai Airlines, had been disastrous.

“Thai Airlines just canceled at 4:21 a.m. and didn’t offer anything else. No phone call and no alternative option.”

Schuman had originally been due to fly business class with Thai Airlines from LHR, and has been forced to book a new last-minute ticket flying with Turkish Airlines at an inflated cost in a lower cabin.

“The cost difference is not comparable,” Schuman said, “Only economy was left today and we had booked business class flights. Even a premium economy flight was around $1,500 more today than the business single we had booked.”

Which airlines are affected?

British Airways had the largest share of flights (51%) scheduled to take off from LHR today, followed by Virgin Atlantic and Lufthansa.

As of 10:15 a.m. GMT, British Airways had canceled 257 of its scheduled flights for the day, which, according to FlightAware, amounts to around 36% of the airline’s schedule.

Heathrow services flights from four major U.S. carriers: American Airlines, Delta Air Lines, United Airlines and JetBlue.

The fire caused chaos on the busy overnight travel corridor from North America to Heathrow, with some planes already in the air when the fire broke out at approximately 11:23 p.m. GMT.

Some flights chose to divert, like British Airways flight 190 from Austin-Bergstrom International Airport (AUS), which diverted to Dulles International Airport (IAD) after three hours and 36 minutes of flying time.

Japan Airlines flight 41 from Haneda Airport (HND) to Heathrow, having completed a large portion of its long-haul sector when the fire broke out, opted to divert to Helsinki Airport (HEL) in Finland.

While this is more than 1,000 miles from London, Helsinki is home to Japan Airlines Oneworld partner Finnair (as well as being another Japan Airlines destination), which the airline may have considered a better option to help get passengers to their final destination than diverting a U.K. airport it does not regularly fly to.

One of the most unfortunate flights affected by this event was Air Canada’s flight 854, departing from Toronto Pearson Airport (YYZ) to Heathrow. With an average flight time of under seven hours across the Atlantic, this flight got around halfway to its destination before diverting to Canada’s Goose Bay Airport (YYR), landing six hours after departure.

This airport was made famous in the Broadway musical “Come From Away” when 7,000 passengers were diverted to Goose Bay following the September 11 event.

What caused the fire?

The London Fire Brigade was alerted at 11:23 p.m. GMT to a fire at an electrical substation operated by the National Grid on Nestles Avenue in Hayes after a transformer was found to be alight — around 5 miles and just a 15-minute drive from Heathrow Airport.

Ten fire engines and around 70 firefighters were mobilized to respond to the incident, which was brought under control at around 6:28 a.m. GMT. There were no reports of any injuries. The cause of the fire is currently unclear and the LFB is working closely with the Metropolitan Police Service on the investigation into the cause of the fire.

“This was a very visible and significant incident, and our firefighters worked tirelessly in challenging conditions to bring the fire under control as swiftly as possible,” said Pat Goulbourne, Assistant Commissioner of the London Fire Brigade. “Thanks to their efforts and coordinated multi-agency response, we successfully contained the fire and prevented further spread.”

Gouldbourne added that the LFB would continue to be present at the scene throughout the day, assisting National Grid as they assessed the site.

“A fire at our North Hyde substation in West London has damaged equipment, leading to a loss of power supply in the area,” said a National Grid spokesperson. “We are working at speed to restore power supplies as quickly as possible.”

As of 6:00 a.m., power had been restored to around 62,000 customers; it is currently unclear whether this includes power restoration at Heathrow Airport.

Due to the high levels of smoke in the area, local residents were advised to keep their windows and doors closed.

Bottom line

Following a fire at a nearby power station, London’s Heathrow Airport — the second busiest airport in the world — was forced to close on Friday. Currently more than 1,000 flights are been affected, with more expected to follow as flight operations are thrown out of sync across the weekend.