Heathrow Airport in London was plunged into chaos after a fire at an electrical substation shut down operations at one of Europe’s busiest air hubs, forcing the airport to cancel or divert more than 1,000 flights on Friday and removing a global linchpin of air travel.
Heathrow’s chief executive, Thomas Woldbye, described the disruption as “unprecedented,” telling reporters on Friday that the airport had lost power equal to that of a midsize city, and that though a backup transformer worked as it should, there had not been not enough to power the entire airport.
But he said, “We expect to be back in full operation, so 100 percent operation as a normal day,” by Saturday.
The British authorities said the counterterrorism police would lead the investigation into the cause of the blaze, which broke out at an electrical substation in North Hyde, northeast of Heathrow. But the Metropolitan Police in London said later Friday, “After initial assessment, we are not treating this incident as suspicious, although inquiries do remain ongoing.”
It was too early on Friday to calculate the precise cost of the outage. But the outage raised questions about the resilience of Britain’s largest airport and why it appeared to be so reliant on a single electrical substation.
Residents of the Hayes neighborhood near the airport described hearing two loud bangs and seeing “a massive ball of flame” shoot into the sky on Thursday night. Minutes later, the airport said it was shutting down all air traffic, incoming flights were diverted, and passengers at Heathrow were sent home. Nearby residents were also evacuated.
By Friday morning, roads around the power station were cordoned off, and a helicopter hovered above. An odd stillness had descended on Heathrow. The runways were empty, the check-in desks quiet, digital flight information screens were blank, and passageways were dimly lit by emergency lighting. It was a lifeless calm not seen even during the early panicked weeks of the coronavirus pandemic.
Britain’s National Grid said on Friday afternoon that it had reconfigured its network to partly restore power at Heathrow on an interim basis. The London Fire Brigade said in the afternoon that 10 percent of the fire was still burning but that it was under control.
The closure resulted in dozens of flights from the United States landing far from their original destination. They were diverted to airports in Glasgow, Madrid and even Happy Valley-Goose Bay, a tiny town in the Canadian province of Newfoundland and Labrador.
John Connor, 22, sat at Newark Liberty International Airport in New Jersey on Friday, waiting in vain to get home to England after backpacking abroad for two years.
“We sat on the plane for about five hours before they said the flight was called off,” he said. “I’m trying to get a plane somewhere close — Paris, Dublin, anywhere else,” he added. “We’re being told straight up no.”
Frantic travelers swarmed social media to ask airlines about managing canceled flights and upcoming departures, claiming in posts on X that airline apps were lagging in notifying passengers about cancellations and that customer service could not be reached by phone.
Some travelers stuck in Europe were urged to consider traveling to Britain by rail. A Delta spokesperson said the airline would reimburse the cost of traveling to London by train for passengers who had their flights diverted to Amsterdam.
By Friday morning, only a few British Airways passengers remained camped out in Terminal 8 at Kennedy International Airport in New York. After making new travel arrangements, some waited for cars to take them to nearby hotels. Others said they planned to spend all day Friday in the terminal.
Some airlines affected by the outage said they would issue waivers allowing free rebookings, including British Airways, Delta Air Lines, American Airlines and United Airlines. Cirium, an aviation data company, estimated that as many as 290,000 passengers could be affected by Heathrow’s closure.
By late Friday, several flights had landed at Heathrow, as the airport began to rumble back to life, about 16 hours after the fire. The first to touch down was a British Airways plane. It had not traveled far, arriving from Gatwick Airport in London after being diverted there from its original destination, Singapore, according to the flight-tracking service FlightAware.
A Heathrow spokeswoman said the airport was working to first restore “repatriation flights and relocating aircraft” as it sought to untangle a day of disrupted service. Officials said that airlines would make it a priority to also relocate planes and crews and bring in flights diverted to other cities.
Britain’s Department of Transport said it was temporarily lifting restrictions on overnight flights to ease congestion while Heathrow Airport resumes normal operations.
But the chief executive of British Airways, Sean Doyle, warned earlier that Heathrow’s closure would have “a huge impact” on the airline’s customers over the coming days. British Airways had been set to operate more than 670 flights carrying about 107,000 customers on Friday, and similar numbers were planned over the weekend, he added.
“We have flight and cabin crew colleagues and planes that are currently at locations where we weren’t planning on them to be,” he said.
The Heathrow crisis was likely to upset not only the movement of people, but the flow of goods, as well. The closure of such a crucial aviation hub, even for a short while, would cause delays and logistical headaches for the many businesses that ship products through Heathrow, supply chain experts said.
Heathrow has two runways and four terminals that serve more than 230 destinations in 90 countries. Last year, about 83.9 million passengers and 1.7 million tons of cargo were flown through the airport. It is the third-largest hub for air cargo in Western Europe, measured in metric tons shipped. Goods worth nearly 200 billion pounds ($258 billion) went through Heathrow in 2023, about a fifth of the value of the British goods trade.
“Goods move around the globe in a really precise, timed way on a daily basis,” said Ben Farrell, chief executive of the Chartered Institute of Procurement and Supply, a global network of supply chain professionals based in London. “Any disruptions to any part of that leads to a knock-on effect elsewhere.”
British businesses will likely be most affected, experts said. Global trade can be handled by other large airports in Europe, said Eytan Buchman, chief marketing officer at Freightos, a digital shipping marketplace. “This will likely be a localized problem rather than a broader European or global one,” he said.
Mr. Woldbye, Heathrow’s chief executive, apologized to travelers for the shutdown and said the airport had done well to resume flights by Friday evening, given the scale of the outage. But he said such disruption had “never happened before.”
The closure of Heathrow came 15 years after one of Europe’s most severe air travel disruptions, when a volcano eruption in Iceland sent ash miles into the sky and obstructing travel for millions, including at Heathrow.
The ash cloud grounded more than 100,000 flights over nearly a week in April 2010 as it drifted across Northern Europe, including the English Channel. The airline industry’s losses from the volcanic disruption were estimated at $1.7 billion.
Reporting was contributed by Christine Chun, Michael Levenson, Michael D. Shear, Peter Eavis, Christopher Maag, Ivan Penn, Stephen Castle, Niraj Chokshi, Ceylan Yeğinsu and Claire Moses.