In an unprecedented move, London Heathrow Airport (LHR) has closed entirely for nearly 24 hours following what officials are describing as a “significant power outage.” The closure, which began late last night, has thrown air travel into chaos, with thousands of flights canceled or diverted and tens of thousands of passengers left stranded.
London Heathrow Airport Closed Until 11:59 PM On March 21, 2025
Let’s unpack what happened and what this means for you if you were planning to travel through Heathrow today.
The Incident
Late Thursday night, a fire erupted at an electrical substation in Hayes, approximately 1.5 miles from Heathrow. The London Fire Brigade dispatched ten fire engines and around 70 firefighters to combat the blaze, leading to the evacuation of approximately 150 residents from nearby properties as a precautionary measure. The fire caused a significant power outage, affecting not only the airport but also thousands of homes in the surrounding area.
Airport Closure and Immediate Impact
Heathrow Airport officials announced the closure on X, stating: “To maintain the safety of our passengers and colleagues, Heathrow will be closed until 23h59 on 21 March.” They advised passengers not to travel to the airport and to contact their airlines for further information.
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
The sudden shutdown led to immediate chaos, with numerous flights either canceled or diverted to other airports. For instance, a Qantas flight from Perth was redirected to Paris Charles de Gaulle Airport, and a United Airlines flight from New York was diverted to Shannon Airport in Ireland. Passengers on these flights faced unexpected layovers and additional travel complications.
Passenger Experience: Frustration and Confusion
The abrupt closure left thousands of passengers stranded both at Heathrow and at other airports. Many expressed frustration over the lack of timely information and the challenges in rebooking flights. Social media platforms were inundated with complaints about long lines at customer service counters, inadequate accommodations, and the overall lack of clear communication from airlines and airport authorities...though I’m not sure now is the time to be hurling blame toward any party.
⛔️𝗕𝗥𝗘𝗔𝗞𝗜𝗡𝗚 𝗡𝗘𝗪𝗦 𝗟𝗜𝗩𝗘
HEATHROW AIRPORT #LHR IS NOW CLOSED ALL DAY FRIDAY MARCH 21, 2025 DUE TO A FIRE NEAR A SUBSTATION NEXT TO THE AIRPORT. pic.twitter.com/gMpoo27BVg— Ꮃꭺꮮꮮ Ꮪꭲꭱꭼꭼꭲ Ꮪꮋꭼꭼꭲ (@wallstreetsheet) March 21, 2025
Airline Response And Compensation
Airlines operating out of Heathrow, including British Airways and Virgin Atlantic, are facing significant operational challenges. While some carriers offered hotel accommodations and meal vouchers, the sheer volume of affected passengers has made it impossible to serve everyone in a timley way. Under UK and European Union regulations, passengers may be entitled to compensation for canceled or significantly delayed flights; however, I think it’s safe to say the extraordinary nature of this incident will provide a force majeure exception to delay compensation, though not for meals and lodging. Affected travelers should contact their respective airlines to inquire about refunds, rebooking options, or compensation…I recommend X or WhatsApp as the generally fastest way to reach an agent.
Technical Investigation And Safety Measures
The exact cause of the fire at the electrical substation remains under investigation. Authorities have not ruled out any possibilities, including technical failures or external factors. The London Fire Brigade’s Assistant Commissioner, Pat Goulbourne, described the incident as “a highly visible and significant” event (see video above), emphasizing that firefighters are working diligently under challenging conditions to control the blaze. A 200-meter safety cordon has been established around the site, and residents in the vicinity have been advised to keep windows and doors closed due to the significant amount of smoke produced by the fire.
Broader Implications and Future Considerations
Heathrow Airport, one of the world’s busiest international travel hubs, handles over 80 million passengers annually. This incident highlights the vulnerability of critical infrastructure to unforeseen events and underscores the need for robust contingency planning. The closure’s ripple effects are expected to disrupt global flight schedules for several days, affecting not only passengers but also cargo operations and airline logistics. We should “let the dust settle” first, but this is an issue we will return to.
Those with imminent travel plans through Heathrow should proactively contact their airlines to explore alternative arrangements. Avoid traveling to the airport until normal operations resume. London Underground service to Heathrow on the Elizabeth Line has been suspended.
Gradual Reopening and Long-Term Impact
Heathrow officials announced early this morning that partial operations would resume within 24 hours, but it could take days—or even weeks—for schedules to fully recover. The ripple effects of the closure will impact global flight networks for the foreseeable future. A Heathrow spokesperson said:
“We are prioritizing the restoration of critical systems and coordinating with airlines to ensure a safe and orderly resumption of service.”
For now, travelers are advised to check their flight status before heading to the airport and to explore alternative travel options where possible.
CONCLUSION
As someone who flies through Heathrow regularly, it’s difficult to overstate the scale of this disruption. Heathrow is one of the world’s busiest airports, and its temporary closure will likely constitute the most disruptive day in Heathrow’s history.
The coming days will reveal more about the cause and handling of this incident—but for now, Heathrow passengers are left with little more than uncertainty and frustration.
Stay tuned for more updates as the situation develops.
That’s a lot of flights from the U.S. that had to return back. I can’t even imagine the logistics of all this. Clearly one of the major meltdowns of 2025. What’s odd is that how does a fire a few miles away shut down the busiest airport? I am unclear as to how this affected Heathrow operations other than rail?
Over dependence on electricity and computers .
Some flights are still on their way to LHR. Will they divert?
The United SFO-LHR flight that normally arrives around 2 pm has been cancelled.
The Virgin Atlantic SFO-LHR flight that normally arrives at around 10:30 pm is one-third of the way to LHR.
The Air Canada YVR-LHR flight has departed.
They are all diverting. I am hearing that Canada is getting a lot of them. As crews time out etc Canada becomes the defacto safety net for this. Given the timing, only the earliest from the US would divert to Ireland, France, etc. Most would be over Canada – or late enough from the U.S. to never even depart.
This is why a major city can’t be served by just one international airport. Imagine there were 4-5 other airports in the London metropolitan area, each serving million, even tens of mullions of passengers per year.
Capacity could be diverted, causing just a mild inconvenience.
Gatwick, City, Luton, Stansted?
A few flights diverted to Gatwick but not as many as I would think. Gatwick is crowded already.
Goose Bay got at least 2 diversions, AC and UA
Shannon got a few
Qantas diverted possibly 2 flights to CDG
FRA got a few, including SQ flights
BCN very few
BHX and MAN very few
Quite a few US originating flight went back to major US hubs. One AA flight went to Bangor, Maine.
And Southend
What an expensive mess. Shocking that LHR doesn’t have its own substation for security reasons.
Anyone who needs to leave the city today should check flights out of BHX, it’s only one hour on a direct train from Euston and will certainly be less inundated than the airports with London in their names.
BHX is decent with flights (4x daily to AMS, CDG via AFKL, 3-4X daily to ZRH and FRA via LH/LX, 5x daily to DUB via EI in addition to FR, LS. U2, BY having operating bases) and the Aspire lounge is serviceable. The only issue is that sometimes the lines for security can be horrid, so I recommend that you get priority security (through status or pay 10 pounds or so extra).
According to reports, there is insufficient backup power because of Netzero “efforts.”
They replaced diesel generators with something called biomass generators (burning poop like cavemen?) and now untold extra gallons of Jet A will be burned to try and restore order and get people home.
But not to worry…Starmer will arrest a few pensioners for Facebook memes and that will solve the problem.
@AndrewH … +1 . He will also arrest those who publicly bow in prayer .
Heathrow is a ghastly airport with lousy forgotten infrastructure and venal profit-centred management with no interest in improving the experience.
Best thing for all will be if Heathrow is permanently closed after this. Customers can get on the Eurostar to CDG and will still be at their destination in good time.
The organization of Heathrow always reminds me of the Monty Python sketch with an architect showing off his new design in which people walk along a corridor onto a series of rotating knives… “Yes,” he says, “I mainly design abattoirs”
Yeah, this will take couple of weeks to get back to normal.