More than 1,300 flights to and from the UK’s largest airport will be disrupted on Friday (March 21) due to the full-day closure following a fire at a nearby electrical substation.
Additionally, thousands of homes have been left without power and more than 100 people were evacuated after a transformer within the North Hyde electrical substation caught fire in west London.
The airport, which is supplied by the substation, said it was among those impacted by the power outage.
Due to a fire at an electrical substation supplying the airport, Heathrow is experiencing a significant power outage.
To maintain the safety of our passengers and colleagues, Heathrow will be closed until 23h59 on 21 March.
Passengers are advised not to travel to the airport… pic.twitter.com/7SWNJP8ojd
— Heathrow Airport (@HeathrowAirport) March 21, 2025
Online flight tracking service FlightRadar24 said the closure would affect at least 1,351 flights to and from Heathrow.
It said 120 flights to the airport were in the air when the closure was announced.
A Heathrow spokesperson said: “Heathrow is experiencing a significant power outage across the airport due to a large fire at a nearby electrical substation. 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. We expect significant disruption over the coming days and passengers should not travel to the airport under any circumstances until the airport reopens.
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“We will provide an update when more information on the resumption of operations is available. We know this will be disappointing for passengers and we want to reassure that we are working as hard as possible to resolve the situation.”
How to check Heathrow Airport flight status
If you were due to travel from Heathrow Airport on Friday, you can check the status of your flight online.
Online tracking services showed flights being diverted to Gatwick, Charles de Gaulle Airport in Paris and Ireland’s Shannon Airport.
Scottish and Southern Electricity Networks said on X there was a large-scale power outage in Hayes, Hounslow and the surrounding areas impacting more than 16,300 homes.
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A National Grid spokesperson said the fire had damaged equipment and they were “working at speed to restore power supplies as quickly as possible”.
London Fire Brigade said 10 fire engines and around 70 firefighters were on the scene at Nestles Avenue in Hayes.
Assistant commissioner Pat Goulbourne commented: “This is a highly visible and significant incident, and our firefighters are working tirelessly in challenging conditions to bring the fire under control as swiftly as possible.
“The fire has caused a power outage affecting a large number of homes and local businesses, and we are working closely with our partners to minimise disruption.”
Footage posted to social media showed huge flames and large plumes of smoke coming from the facility.
Emergency services were called to the scene at 11.23pm on Thursday (March 20). The cause of the fire is yet to be determined.
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Mr Goulbourne said firefighters urged people to take safety precautions as crews worked to extinguish the blaze.
“This will be a prolonged incident, with crews remaining on scene throughout the night,” he said.
“As we head into the morning, disruption is expected to increase, and we urge people to avoid the area wherever possible.”
London Ambulance Service and Metropolitan Police both confirmed they were on scene supporting fire crews.
