Major Fire at London Substation Cuts Power to Heathrow Airport, Disrupting Travel
A major fire in London cut the power to Heathrow Airport on Friday, disrupting flights and travel plans for thousands of people.
The airport said in a statement that a fire at an electrical substation that supplies the airport caused a “significant power outage” but was safely resuming flights late in the day on 21 March.
“To maintain the safety of our passengers and colleagues, Heathrow will run a reduced operation prioritizing repatriation and relocation of aircraft,” the airport said. “Passengers should contact their airline for further information. We apologize for the inconvenience.”
The fire broke out at the North Hyde substation in West London, about 2 miles from the airport, at approximately 11:20 p.m. local time on 20 March. The London Fire Brigade responded within five minutes with 10 fire engines, two bulk foam units, and one high volume pump, all manned by 70 firefighters, to contain the fire.
The blaze burned more than 25,000 liters of cooling oil at the substation, knocked out power to 66,900 customers, and shut off a backup generator that supplies Heathrow, ultimately causing a major power outage to the airport.
The London Fire Brigade said that it will remain on the scene to secure access for specialist power network engineers to restore power. Disruptions to electrical service are expected to continue, and the brigade is urging people to avoid the area.
Our firefighters are working tirelessly to bring the fire in #Hayes under control. Part of a transformer remains alight.
— London Fire Brigade (@LondonFire) March 21, 2025
As we head into the morning, disruption is expected to increase, and we urge people to avoid the area wherever possible https://t.co/IrOHNJTpqp pic.twitter.com/x8IY0srTD0
Authorities are investigating the cause of the fire, with counterterror detectives leading the effort because of the blaze’s impact on critical national infrastructure.
“We don’t know the cause of this fire. It’s obviously an unprecedented event,” said UK Energy Secretary Ed Miliband in an interview with the Associated Press (AP).
Immediate Impact
Heathrow is one of the busiest airports in the world and the United Kingdom’s main travel hub that serves about 200,000 passengers per day. The incident affected more than 1,000 flights—as of mid-morning on Friday—and the impact will likely last several days as travelers reschedule and airlines shuffle planes and crews.
British Airways, for instance, cancelled all of its short-haul flights to and from Heathrow on Friday and said that it is reviewing its long-haul schedule for Friday and beyond.
Flights that were in the air when the power outage struck were rerouted to other airports in Europe, including Frankfurt Airport and Adolfo Suátos Madrid-Barajas Airport.
Kevin Coffey, vice-chair of the ASIS International Travel Risk Management (TRM) Community Steering Committee, tells Security Management that organizations that contract with a travel risk management company will have their travel desks work to rebook affected employees or attempt to get them to different airports to fly out.
One of the biggest issues right now is that due to the high demand for alternative routes, travelers are communicating that they are having issues getting access to trains to get to an alternative airport, as well as issues finding their luggage, Coffey explains.
To assist stranded travelers, Eurostar added extra trains between London and Paris on Friday.
“If you’re booked to travel, please ensure that you arrive at the station at the recommended time stated on your ticket,” Eurostar said in a statement. “Our stations will be busy, and you’ll need to allow enough time for ticket, security, and passport checks before boarding your train.”
One traveler reported considering booking a rental car to drive to another airport, but Coffey says that is a risk that organizations need to assess since driving in a foreign country might involve using opposite lanes and unusual signage.
“What if you have somebody who is more of a timid traveler? Do you really want that person doing that? Is it really important?” Coffey asks. Instead, he recommends having a decision team in place that could potentially book a car service for that employee to transport him or her to another transit hub.
“If this person has a critical position where they have to get out, you have to find that and build this consideration in,” Coffey adds. “And it might just be hiring a driver to help get that person out because they’re not comfortable driving.”
Coffey also stresses that this is an important moment to use the company’s Travel Registration Program—a program that most organizations create that employees are required to book their travel through, providing access to their itineraries to both the organization and a travel risk management company (TRMC). This type of program would make it easy for organizations to determine which employees were at—or traveling to or from—Heathrow on Friday and will need assistance.
Organizations can also make use of their TRMC applications that can push out notifications to affected employees, prompting them to check in and providing guidance on next steps to manage the disruption. For companies without that asset, however, Coffey says it’s critical that employees know who to call at the company for assistance.
“This is a travel disruption. Some folks are going to call it an emergency, but at the end of the day, this is a travel disruption just like a hurricane that shuts down the airport,” Coffey adds. “But it’s important that the employees know where they would call in an emergency to check in and get assistance.”
To facilitate this process in the future, Coffey recommends providing employees with a wallet-sized card that has the emergency contact information listed on it. This ensures that if the employee loses access to their phone—or its battery dies in transit—that they can still reach their contact to check in and get further assistance.
Along with disrupting travel for people, the incident has also disrupted cargo transit, stranding approximately 4,000 tons of cargo, said Anita Mendiratta, an aviation consultant who spoke with the Associated Press (AP).
“There will be two things that will be happening as a priority number one shall we say. First is airport operations and understanding, from an electrical system point of view, what has been impacted, if anything,” Mendiratta said. “Did anything short out, for instance? What needs to be reactivated? And then how do you literally turn the airport back on again? Passenger and cargo.
“On top of that, there’s the issue of actually managing the human component of it. You have passengers that are impacted, crew are impacted, and operations—so being able to re-mobilize everything,” she continued.
The Investigation
The Met Police’s Counter Terrorism Command is leading the investigation into the fire because of the location of the substation and its impact on critical national infrastructure, The Guardian reported.
The command has “specialist resources and capabilities within that command that can assist in progressing this investigation at pace to minimize disruption and identify the cause,” a spokesperson for the Met Police said.
Alan Mendoza, executive director of the UK-based think tank Henry Jackson Society, says that critical national infrastructure sites like power plants and airports might be obvious targets for on-the-ground sabotage by agents of hostile foreign powers.
“Attacking such targets causes widescale disruption at the least and potentially civil unrest at the most, depending on how serious any attack might be,” Mendoza tells Security Management via email. “Obviously while the Heathrow fire is not currently considered a terrorist incident as the investigation is ongoing, Heathrow is a tempting target for foreign state actors, and the ease with which its operations have been shut down by one fire is therefore alarming for UK resilience.”
The UK needs investment in its critical infrastructure, including power and energy, transportation and communications networks, Mendoza adds.
“Our national security is dependent not only on all of these functioning effectively and to the best standards possible, but also on their being appropriately protected to defend against accidents or hostile damage,” Mendoza says. “What is quite clear given the ease with which Heathrow has been stricken is that there are obvious concerns about whether the UK has hardened its systems sufficiently to prevent future problems of a similar nature.”
In response, Mendoza is advocating for a full national audit conducted by the UK central government to prevent future disruptions like that at Heathrow this week.
“The audit would look at each area of critical national infrastructure, consider a resilience percentage given the nature of backup systems available in the case of crisis, and then suggest remedial actions to improve resilience in each of the areas concerned.”
There is no indication that a nation-state was involved in the fire, but critical infrastructure has been a frequent target in recent geopolitical conflicts. Earlier this week, for instance, the Center for Strategic and International Studies (CSIS) released a major report on Russia’s sabotage and subversion campaign against European and U.S. targets in Europe.
About 27 percent of the attacks were against transportation targets—trains, vehicles, and airplanes—and the most common methods involved explosives and incendiaries, according to Russia’s Shadow War Against the West.
“Private industry, especially the defense industry, was also a common target of Russian activity. The two largest European donors of military aid to Ukraine—Germany and the United Kingdom—experienced attacks on numerous defense manufacturing plants,” the report explained. “In May 2024, for example, a major fire broke out at a Diehl Group factory in Berlin, which manufactures IRIS-T surface-to-air missiles used in Ukraine. A month earlier, there was an explosion at a weapons manufacturing site in South Wales belonging to BAE systems, the United Kingdom’s largest arms manufacturer, which has supplied ammunition, weapons, and other defense equipment to Ukraine. A BAE investigation into the incident found no evidence of sabotage.”
For more on travel security, stay tuned for our April Security Technology issue that will be entirely focused on travel risk management and feature contributions from the ASIS TRM Community.
