Counter-terrorism police are leading the investigation into the fire that has shut down Heathrow airport.
The Telegraph understands specialist detectives are on site at the North Hyde electrical substation after a blast there shortly before midnight.
The Metropolitan Police said there is “currently no indication of foul play” but said it would “retain an open mind” and that officers from Counter Terrorism Command would now lead the investigation because of “the impact this incident has had on critical infrastructure”.
The officers – also known as ‘SO15’ – will play a key role to try to establish whether or not any hostile agents were involved in triggering the blaze.
At least 1,351 flights going to and from the airport have been impacted by the closure, with up to 291,000 passengers thought to be affected. The National Grid said this afternoon that power has now been restored to the airport.
It comes as Downing Street said there were “questions to answer” over how a single fire was able to shut down the airport.
A No 10 spokesman said: “There are questions to answer and we will be asking those to ensure the scale of disruption does not happen again.”
Inbound planes have been diverted to other airports, including Shannon in Ireland and Charles de Gaulle in Paris, with aviation experts saying the impact of disruption is “similar to 9/11”.
A Heathrow airport spokesman said the site will be closed all day and will not reopen until midnight tonight.
In a post on X this morning, Sir Keir Starmer said he was “receiving regular updates” on the situation as he thanked emergency services.
The Prime Minister said: “I know the situation in Heathrow is causing distress and disruption, especially for those travelling or without power in their homes.
“I’m receiving regular updates and I’m in close contact with partners on the ground. Thanks to our emergency workers for keeping people safe.”
Heathrow fire ‘shows UK needs to be more prepared’
The UK needs to be fully prepared for dealing with short term shocks like the Heathrow fire, the National Infrastructure Chair has said.
Sir John Armitt added: “That means building resilience into all systems, regularly stress testing, and increasing cooperation with other operators to identify risks arising from increasing interdependence.
“We’ve been clear the UK needs national resilience standards for our transport, digital, energy and water infrastructure.
“These will give clarity to operators and users about what levels of service they should expect in the face of short and long term disruptions, and ensure regulators have a clear yardstick against which they can ensure sufficient investment in resilience is made, proportionate to the risk.”
Comment: ‘Heathrow fire lays bare Britain’s alarming exposure’
In a disaster movie, Russian and Chinese spies infiltrate our national infrastructure and launch a devastating cyber attack, freezing our transport and communications as a prelude to invasion. The opening scene? Britain’s main airport is engulfed in a fireball, writes Jake Wallis Simons.
We are living in a time when reality is starting to converge with Hollywood doomsday scenarios. Just look at the pictures of the fireball at Heathrow.
You almost expect Tom Hanks to make an appearance as Sir Keir Starmer, with Christopher Walken playing Vladimir Putin and, I don’t know, James Corden as Donald Trump.
But this is serious. Heathrow closed? This sort of scandal hasn’t occurred since the mysterious Gatwick drone incident of 2018, when 140,000 passengers were affected; and before that, the 2010 volcano eruptions in Iceland. The economic damage will be eye-watering. And I can’t be alone in worrying that this is more than a random malfunction.
Power restored to Heathrow Airport, National Grid says
The National Grid has said electrical supplies have been reconnected to Heathrow Airport, writes Gareth Corfield.
The news raises hopes that the airport may be able to re-open tomorrow, although a Heathrow spokesman said the closure will remain in place until at least the end of the day while systems inside the airport’s terminals are turned back on and tested to ensure they are working properly.
A National Grid spokesman said: “Working in partnership with the local network operator SSEN Distribution (SSEN), the network has been reconfigured to restore all customers impacted, including the ability to resupply the parts of Heathrow airport that are connected to North Hyde.
“This is an interim solution while we carry out further work at North Hyde to return the substation and our network to normal operation.
“We are continuing to work closely with all stakeholders to manage this incident, and are focused on returning to normal resilience levels as soon as possible.”
CAA ‘in close contact’ with Heathrow and Government
The Civil Aviation Authority (CAA) said it was in close contact with Heathrow Airport, airlines and No 10.
Selina Chadha, the CAA’s group director for consumers, said: “Passengers are advised not to travel to Heathrow at this time and should contact their airlines for the latest flight updates.
“We appreciate the difficulties that travel disruption causes and we expect airlines to take all necessary steps to support and assist their passengers during this period of disruption.
“The Civil Aviation Authority remains in close contact with Heathrow Airport, airlines and the Government during this time.”
Why MI5 will be checking very carefully for Putin’s fingerprints
A fire the likes of which has never happened before. One which instantly closes Europe’s biggest air hub at a time of rising geo-political tensions, and just as a meeting of the continent’s most senior defence chiefs breaks up. Can it really be a coincidence? asks Paul Nuki.
We don’t yet know what caused the fire which broke out at an electricity sub station which supplies Heathrow in the early hours of Friday morning, but the British security services will be all over it. Every inch of the area will be subjected to a bank of forensic checks as will all CCTV and communications for miles around.
The reason is simple: the fire has all the hallmarks of Russian state-sponsored terrorism – a hybrid form of war that has been raging in Europe for more than three years now.
Ministers and security officials don’t want to alarm the public but there have been sabotage operations recorded in 15 countries including Britain linked to Russian intelligence since Vladimir Putin rolled his tanks into Ukraine in late February 2022. It’s many if you go back to the invasion of Crimea in 2014.
They include train derailments, arson attacks on warehouses and transport planes, assassination plots against industrialists, car rammings, election interference, social engineering and, yes, attacks on vital infrastructure including power and communications lines.
Heathrow: We don’t know when power will be restored
Heathrow said it does not have “clarity on when power may be reliably restored”.
A spokesman 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.

“We expect significant disruption over the coming days and passengers should not travel to the airport under any circumstances until the airport reopens.
“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.”
Heathrow: Our back-up systems worked ‘as expected’
Heathrow Airport has said its back-up systems worked “as expected” in response to the fire.
“We have multiple sources of energy into Heathrow. But when a source is interrupted, we have back-up diesel generators and uninterruptable power supplies in place, and they all operated as expected.
“Our back-up systems are safety systems which allow us to land aircraft and evacuate passengers safely, but they are not designed to allow us to run a full operation.
“As the busiest airport in Europe, Heathrow uses as much energy as a small city, therefore it’s not possible to have back-up for all of the energy we need to run our operation safely.
“We are implementing a process which will allow us to redirect power to the affected areas, but this is a safety critical process which takes time, and maintaining safety remains our priority, so we have taken the decision to close the airport for today.”
BA: Our teams are ‘reviewing long-haul schedule’
British Airways said in a statement it has cancelled “all short-haul flights” scheduled to serve Heathrow on Friday.
A spokesperson for BA said: “Following the power outage that has caused the closure of London Heathrow Airport, we have had to cancel all short-haul flights that were due to operate to and from the airport today.
“Our teams are currently working hard to review our long-haul schedule as well as the implications for our schedule for tomorrow and beyond.
“We will update our customers as soon as possible and we continue to ask them not to travel to Heathrow Airport, but to check on ba.com for the latest flight information.”
Heathrow chief executive has spoken to Transport Secretary
Transport Secretary Heidi Alexander has spoken to Thomas Woldbye, the Heathrow chief executive, about when the airport will reopen, writes Gareth Corfield.
Ms Alexander said: “This morning, I spoke with Heathrow Airport’s chief executive to hear the latest on the unprecedented power outage and I am reassured they’re working tirelessly to reopen the airport as soon as possible,” the Transport Secretary said in a statement.
“I would like to thank everyone involved in responding to this situation – particularly the emergency workers who have worked to contain the fire and keep everyone safe.
“I appreciate how disruptive this situation is for passengers, but until they hear otherwise, the advice remains to avoid travelling to Heathrow.”
Heathrow is currently closed until tomorrow, with flight disruption expected to last for the rest of the weekend.
Tice: We need answers and quickly
Richard Tice, the Reform UK deputy leader, asked whether Heathrow Airport “put profit ahead of reliability”.
He said: “Heathrow management have failed the nation. They have serious questions to answer.
“Why have they left our most critical infrastructure exposed to just one sub station? Where was the back up?
“Is it true the back up was made net zero compliant and it failed when activated? Have Heathrow put profit ahead of reliability? We need answers, and quickly.”
Downing Street: ‘Questions to answer’ over Heathrow fire
Downing Street has said there are “questions to answer” about how a single fire shut down Heathrow airport.
A No 10 spokesman said: “There will no doubt be questions to answer on how this has happened and what can be done to prevent a repeat.”
However, he said the “immediate” priority was to get the situation under control.
He said he did not have any operational updates on the causes of the fire, but that would form part of “any subsequent investigation”.
The spokesman added: “Let’s focus on getting the situation under control and the questions can be posed once that is in hand. That’s the immediate priority.
“But yeah, there are questions to answer and we will be asking those to ensure the scale of disruption does not happen again.”
‘Serious questions’ for BA, says former airline boss
The former boss of British Airways has said the Heathrow shutdown begs some “serious questions” for the airport.
Willie Walsh, Director General of the International Air Transport Association, said: “This is yet another case of Heathrow letting down both travellers and airlines. And that begs some serious questions.
“Firstly, how is it that critical infrastructure—of national and global importance—is totally dependent on a single power source without an alternative.
“If that is the case—as it seems—then it is a clear planning failure by the airport.
“And, from that arises the question of who bears the costs of taking care of disrupted travellers. We must find a fairer allocation of passenger care costs than airlines alone picking up the tab when infrastructure fails. Until that happens, Heathrow has very little incentive to improve.”
Met: We retain an open mind about cause of the fire
A spokesman for the Metropolitan Police said: “We are working with the London Fire Brigade to establish the cause of the fire which remains under investigation. While there is currently no indication of foul play we retain an open mind at this time.
“Given the location of the substation and the impact this incident has had on critical national infrastructure, the Met’s Counter Terrorism Command is now leading enquiries.
“This is due to the specialist resources and capabilities within that command that can assist in progressing this investigation at pace to minimise disruption and identify the cause.”
Residents woke to ‘massive bang’ and windows shaking
Residents on Nestles Avenue in Hayes said they woke to the sound of a “massive bang” and windows shaking as the explosion erupted.
“I was watching a movie when I heard a big bang and my windows were shaking,” Azam Ali, 82, said. “I looked out and then I saw the fire engines, then the firemen were running up to the substation.
“There was massive black smoke and all these flats were evacuated and my electricity went off. I thought it was a gas blow. It was massive. The flames were about 50 metres on top of this building in front with a big black cloud.”
Mr Ali, who has lived on Nestles Avenue since 1985 and used to work in high value cargo for British Airways, questioned how the explosion had cut off electricity to Heathrow.
“How can the outage blow, I don’t know. It’s electric it’s not gas. How can Heathrow depend on this outrage here?
“It was scary but it was very interesting because I didn’t know the cause of it. I can’t understand how that thing blew. It’s so confusing.”
‘Night turned to day’ as fire erupted
Savita Kapur, 51, said “night turned to day” as the fire erupted on Nestles Avenue last night.
“It was the 11.30 at night on the dot and my living room shook. I heard a loud bang, and basically, night turned today within 10 minutes. It was awful.
“I was so scared, I picked up my phone and ran outside. I saw the inferno because it was literally just yards away from my house. I thought, Oh, my God, this is not happening and dialled 999.”
Ms Kapur, who owns her own fashion business, added that the “ground shook” following the second explosion as she evacuated her 80-year-old mother.
“I was quite scared, because if it was windy like this last night, I think the situation would have been a lot worse because of the fire, and then the second explosion went off 12 o’clock. I remember that because I had my elderly mother in the car trying to get her to safety to my sister’s house, and the ground shook because the explosion was that loud and that intense.”
They are now waiting for news on when they can return to their home.
Fire involved 25,000 litres of cooling oil, say London Fire Brigade
The substation fire in Hayes involved 25,000 litres of cooling oil fully alight, the London Fire Brigade (LFB) said.
Speaking to broadcasters at the scene in Hayes, London Fire Brigade deputy commissioner Jonathan Smith said: “At 8.23pm on the evening of the 20th of March, London Fire Brigade received 212 calls to a fire in a high-voltage substation near Heathrow Airport.
“The fire involved a transformer comprising 25,000 litres of cooling oil fully alight. This created a major hazard due to the still live high-voltage equipment and the nature of the oil-fuelled fire.”
The Metropolitan Police declared a major incident for the fire at 12.42am on Friday, Mr Smith said.
Around 10 per cent of the substation remains alight. Some 67,000 households were left without power due to the incident and 5,000 homes remain without power.
There is also no power at Heathrow Airport terminals two or four, Mr Smith said.
Backup generator reports incorrect, say National Grid
A senior National Grid executive has said reports that a backup generator was taken out by the electricity substation fire in Hayes are incorrect, reports Matt Oliver.
The substation hosts transformers, which are used to convert high voltage electricity from the national grid into power that can be distributed to homes.
One transformer was damaged by the late night blaze, with another transformer beside it – one that could have been used as a backup – also damaged by the same fire, the Telegraph understands.
However, a third transformer remains available and has not been damaged by the fire with grid engineers now working to get it online.
Alice Delahunty, president of National Grid’s electricity transmission business, said engineers were also seeking to reroute power to Heathrow from other nearby substations.
She said: “There has been some confusion. There isn’t backup generation, per se, on the substation site. But there are different levels of redundancy, and this is a very significant and serious event, so it has had a wider impact than you would normally expect.
“The challenge we have right now is that we’ve had a very significant fire, and therefore there’s been wider-ranging implications for our network and the distribution network.
“So we’re just very focused on reestablishing other routes by which we can supply Heathrow. We’ve got to reconfigure the network, make the site safe to do that, and that’s what we’re entirely focused on.”
Counter-terrorism police involved in fire investigation
Counter-terrorism police are involved in the investigation into the fire that has shut down Heathrow airport.
The Telegraph understands specialist detectives are on site at the North Hyde electrical substation after a blast there shortly before midnight.
The officers were sent to the scene in Hayes in West London as a “precautionary measure”.
A Metropolitan police source added that the presence did not confirm foul play or sabotage.
Officers from Counter Terrorism Command – also known as SO15 – will play a key role to try to establish whether or not any hostile agents were involved in triggering the blaze.
Hayes schools closed due to Heathrow fire
Six schools in Hayes have been forced to close today because of the fire at the North Hyde Electricity Substation.
In a statement, Hillingdon Council also said that refuse and recycling collections in the area would be affected.
Nestles Avenue Early Years Centre, Pinkwell Children’s Centre, Pinkwell Primary School, Botwell House Catholic Primary School, Dr Triplett’s Church of England Primary School and The Global Academy have all shut today.
Bus routes in the area have further been affected, with diversions in place, while the Elizabeth Line is not running between Hayes and Harlington and Heathrow.
‘I was told by BA my flight would still go ahead’
A woman hoping to fly to Dubai later today travelled to Heathrow Airport after British Airways told her that her flight would still go ahead.
Elvina Quaison, who lives in London, told the PA news agency she had seen news of the fire but was initially assured her flight would still depart.
“My flight’s meant to be at 12.40pm and I’d been checking the news, the websites and my emails,” Ms Quaison told the PA news agency.
“I’m flying with BA and they had said that we should keep an eye on our ‘manage my booking’ and it would give us an update as to what was happening with my flight. So I got a message [at 8am] to say that my flight was departing and that I can go ahead as normal.
“So I’ve come to the airport to make the flight which I was told was flying today and I can’t get to the actual airport … I’m just about to call to see what to do.”
Disruption to continue ‘for the next few days’
Disruption caused by the closure of Heathrow Airport will continue “for the next few days”, the chief executive of an independent travel agent network has said.
Julia Lo Bue-Said, who runs Advantage Travel Partnerships, said: “An incident like this at one of the world’s busiest airports will have a very significant knock-on impact on all travel for the next few days.
“Of course, the priority for everyone is safety and the airport and the airlines will be working hard today to make sure the area is safe, and that they can resume operations as soon as possible.”

Ms Bue-Said noted Friday was typically the busiest day for air travel as passengers return from business trips, go on holiday, and visit friends and family.
“London airports would have been busy today already and this incident will exacerbate it further,” she added.
“For anyone that has a flight booked out of Heathrow today, and had booked via a travel agent, I recommend contacting them in the first instance as they will be able to provide the latest information and advice.”
Sadiq Khan: Heathrow closure will be ‘hugely frustrating’
Sir Sadiq Khan has acknowledged the closure of Heathrow Airport will be “hugely frustrating”.
In a statement, the Labour Mayor of London said: “Heathrow Airport is closed today due to a power outage caused by a fire at a nearby electrical substation. The fire is having a significant impact on the local area with the airport closed, other businesses affected and homes left without power.
“I know this will be hugely frustrating for the many thousands expecting to travel to and from Heathrow today, the families who have had their power cut and the commuters who have had their journeys disrupted.
“I’d like to thank the emergency services who have been working hard overnight to tackle the fire, and I remain in close contact with them, as I have been overnight. Thankfully, there are no reports of any injuries.
“Electricity suppliers are working hard to restore power, but Heathrow Airport have said they will be closed all day and has warned of significant disruption over the coming days.
“Passengers are advised not to travel to the airport under any circumstances and I urge Londoners to follow the advice of emergency services and their travel providers.”
Hotels accused of ‘absurd’ price increases
A video producer has accused hotels of “absolutely absurd” price increases following the Heathrow closure.
Louis, who did not wish to share his surname, was due to fly back to Dublin with Aer Lingus on Friday but his trip home is among more than 1,300 flights that have been cancelled.
The 28 year-old told the PA news agency he was forced to book a new room at a different hotel, saying nearby hotels had increased their prices as a result of the disruption.
He said his original room cost around £90, but he had seen the same room on Booking.com for £280.
“They’ve actually doubled, if not, in some cases, tripled the prices of the rooms based on what’s going on, which is absolutely absurd,” Louis said.
“They’re profiting off of people’s misfortunes in this. I don’t know how that’s allowed… It’s frustrating, but it’s just beyond control.”
Airports need back-up plans, say stranded couple
One couple have been left worried they may not see their son for another year after the cancellation of flights to San Francisco.
Barbara Owen, 72, and Peter Marsden, 69, had driven down from Manchester on Thursday before they woke to news of the closure this morning.
“It’s a nightmare,” said Mr Marsden.
They only see their eldest son and grandchildren once a year, meaning their reunion could be postponed depending on the backlog of flights.
“It highlights the fact there should be a back-up plan for airports,” Ms Owen said.
“We have to wait for them to wake up to plan what we’re going to do.”
Up to 291,000 passengers disrupted by Heathrow closure
Around 291,000 passengers were scheduled to fly in and out of Heathrow airport today, according to Cirium, the aviation analytics site.
The airport was scheduled to see 665 departures on Friday, equating to over 145,094 seats, with a further 669 flights due to arrive.
British Airways has the largest share of flights from the airport today at 51 per cent, which is followed by Virgin Atlantic and Lufthansa.
