‘Catastrophic’ Transformer Fire Closes Heathrow Airport, Global Travel Disrupted, Sabotage Question Immediately Raised

One of the world’s busiest airports is shut for an unprecedented full working day, disrupting air travel worldwide, after a major fire took out not only its power supply but backup systems as well.

Serious questions were immediately raised about the resilience of critical national infrastructure and the possibility of sabotage after London Heathrow was force to close by a major power cut. Airport management say it will remain closed until 2359 GMT (1959 Eastern) tonight.

One of the world’s busiest airports, Heathrow will typically handle over 1,300 flights in a day and analysis by Flightradar24 states “at least 1,351” flights to and from the airport will be impacted today. Yet the disruption will inevitably go far further and impact thousands more flights, as Heathrow is a major hub for refuelling flights and crew changeovers.

Those aircraft that were to be on cancelled flights will not now be positioned correctly for their subsequent planned journeys, meaning disruption could last for hours or days more.

UPDATE 1230: Counter-terror police leading investigation, but no indication of cause yet

The UK’s counter-terrorism police have gone from assisting enquiries to leading the investigation, but the Metropolitan Police say this is because counter-terror officers have specialist skills in investigation and the cause of the blaze that took out one of the UK’s largest power transformer sites overnight is still unknown. The 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 sub-station 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.

We now know that, as suspected, the transformer oil that both cools and insulates the high-voltage equipment was contributing to the fire. The London Fire Brigade said there was 25,000 litres (6,600 U.S. gallons) of mineral oil “fully alight”. Right now, that has been reduced by the efforts of the Fire Brigade to ten per cent alight.

Meanwhile, the International Air Travel Association (IATA), a trade body representing the interests of airlines worldwide, has some serious criticism for Heathrow Airport itself, pointing out today’s major disruption appears to be caused by a major transport node not being prepared for disasters but airlines will be expected to pick up the costs.

Their statement said:

This is yet another case of Heathrow letting down both travelers 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 travelers.

Unless Heathrow takes on the consequences of its failures, it has “very little incentive to improve”, the body said.

Planes are parked at the Terminal as Britain’s Heathrow Airport has closed for the full day Friday after an electrical substation fire knocked out its power, disrupting flights for hundreds of thousands of passengers at one of Europe’s biggest travel hubs in London, Friday, March 21, 2025.(AP Photo/Kin Cheung)

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British newspaper The Guardian cites an air industry insider who calls the level of disruption to global air travel looming “unheard of” and “catastrophic”.

The airport and over 60,000 “customers” lost power overnight when a fire broke out at a major electrical substation at North Hyde, West London. An eyewitness said there was a “bright flash of white” light from the transformer immediately proceeding the power going out. The fire burned ferociously through the night and while the London Fire Brigade say it is now under control, it continues to burn at the time of going to press.

Typically, large transformers are oil-cooled but explosions of this magnitude are extremely rare.

An investigation into the cause of the fire is now underway between the Fire Brigade’s experts and the Metropolitan Police. While no reason has yet been stated for the fire, given the sudden prevalence of once-in-a-lifetime tier ‘accidents’ in Europe and the blame being unfailingly laid at Russia’s door, questions of whether this is the latest act in what is called Moscow’s ‘hybrid warfare’ campaign were inevitably and quickly raised.

Others pointed to the fact one of the world’s most consequential airports could be totally shut by a fire at just one airport begs serious questions about the resilience of Britain’s critical national infrastructure.

Britain’s Energy Minister Ed Miliband — usually only known for his dogmatic crusade for net zero, rather than interest in hardening critical infrastructure against accident or attack — toured the television and radio studios on Friday morning speaking about the substation fire, which he called “catastrophic”. Betraying an apparent lack of understanding about what an electricity substation is for, he told the Good Morning Britain programme, for instance: “I’ve spoken to the National Grid this morning, we’ve seen a catastrophic fire… at the substation, it not only affecting the generation from the substation but as I understand it some backup generation that is in place”.

He said: “National Grid said in their conversation with me this morning said it is a fire they’ve never quite seen anything like the scale of what happened before, and it was the seriousness of the fire which knocked out the backup as well. But it makes Heathrow look quite vulnerable and therefore we’ve got to learn lessons, as I say, about not just Heathrow but how we protect our major infrastructure.”

He told radio station LBC that “There’s no suggestion that there is foul play”, but in context this appeared to mean there was no information about the cause whatsoever yet, rather than the evidence to hand appeared to make deliberate action unlikely.

Member of Parliament Richard Tice spoke to GB News on Friday morning to allege Heathrow’s hardness against extraordinary events had been weakened by a push to decarbonise the airport. The Reform MP said he had spoken to an industry insider who told him the airport had substituted diesel generators for a biomass generator.

“Their Net Zero-compliant backup system has completely failed in its core function at the first time of asking”, Tice said. Heathrow certainly has a biomass energy system, but whether this was relevant to today’s “catastrophic” power failure has not yet been positively proven.

This story is developing, more follows