Europe’s busiest airport, London Heathrow, will be closed all day on Friday, the 21st of March, causing travel chaos after a fire broke out at a nearby electricity substation, knocking out power, according to Politico and the BBC.
Heathrow Airport advised passengers not to travel to the airport and to contact airlines for further instructions, with a statement on social media saying that no flights would operate until at least “11.59pm on the 21st of March”.
Heathrow is the busiest airport in Europe and the UK, with more than 1 300 flights a day, meaning that thousands of travellers will be affected by the closure.
What happened at Heathrow?
On Thursday evening, a fire broke out at an electricity substation less than 5 km from Heathrow Airport.
Around 70 firefighters and ten fire engines worked to extinguish the fire at the substation, which authorities said on Friday morning was under control. The fire caused a power outage affecting 4 900 homes, local businesses and Heathrow Airport.
🚨HEATHROW AIRPORT CLOSED AFTER MAJOR SUBSTATION FIRE LAST NIGHT
– 200,000 passengers stranded– Homes all across West London have been affected by the power outage
This is insane pic.twitter.com/hnf2faEmjB
— Basil the Great (@Basil_TGMD) March 21, 2025
About 150 people were evacuated from the surrounding area and an area within a 200 metre radius was cordoned off. Firefighters advised local residents to keep windows and doors locked to prevent smoke entering homes
By Friday morning the authorities had restored power to several properties.
Who is affected?
According to flight tracking website Flightradar24, 1 351 flights were scheduled at Heathrow on Friday. Many of these will now be cancelled or diverted to other airports. This will cause chaos in the travel plans of thousands of people. Heathrow also acts as an important global hub for passengers continuing on to other destinations.
According to the flight tracking website, flights from Bangkok, New York, Boston and other Heathrow-bound flights were diverted to various destinations including Brussels, Iceland, Canada, Ireland, Cardiff, Manchester, Munich, Frankfurt and Madrid.
Heathrow Airport warned of “significant disruption” in the coming days and urged passengers not to attempt to travel to the airport “under any circumstances” until it reopens.
Was it sabotage?
A statement from the London Fire Brigade said the cause of the fire was not yet known.
British Energy Minister Ed Miliband told BBC radio on Friday morning that “there is no indication that there has been any malicious action”.
However, questions have been raised about Heathrow’s emergency preparedness and resilience.
“It is very unusual” that such an accident “has such a big impact,” said Professor Zheng Lei, chairman of Swinburne University’s Department of Aviation.
We “don’t really understand the details of the situation”, he said, adding that he did not want to speculate on the causes. “But I can say that this is a very unusual event.”
What’s the government response?
UK Transport Secretary Heidi Alexander is briefed on the situation at the airport, which she described as “rapidly changing”, and Energy Secretary Ed Miliband has spoken to National Grid, the company that transmits and distributes electricity in the UK.
“Apparently there has been a catastrophic fire at this substation, which in their experience is unprecedented,” Miliband told the BBC on Friday morning. “The fire appears to have destroyed the standby generator as well as the substation itself. I know they are working as hard as they can to restore power as well as extinguish the fire.”
“There was a back-up generator, but the fire affected that as well, which shows how unusual or unprecedented it was. There is a third standby generator… that they use to restore power. So there are back-up mechanisms, but given the scale of this fire, it seems that the back-up mechanisms have been affected,” Miliband told Sky.
Britain faced similar travel chaos in 2010 when Iceland’s Eyjafjallajökull volcano erupted, causing an ash cloud across Europe. The government responded by convening a COBRA crisis committee. Asked whether a similar response would happen now, Miliband said the government would act accordingly and that he was already in contact with colleagues.