LONDON. Operations at Heathrow Airport have resumed following a major power outage that forced the closure of Europe’s busiest airport on Friday, leaving tens of thousands of passengers stranded and causing widespread travel disruptions across the globe.

The shutdown occurred after a massive fire broke out at a nearby electrical substation on Thursday night, knocking out the airport’s power supply. Heathrow authorities advised travelers to stay away as emergency crews worked tirelessly to restore operations at the world’s fifth-busiest airport.

Heathrow was originally scheduled to handle 1,351 flights on Friday, accommodating up to 291,000 passengers. However, the closure led to mass flight diversions across Britain and Europe, while numerous long-haul flights were forced to return to their departure points. By late Friday, the airport had reopened with a limited number of flights, primarily aimed at repositioning aircraft and bringing planes into London.

“Tomorrow morning, we expect to be back in full operation, to 100% operation as a normal day,” said Heathrow Chief Executive Thomas Woldbye. “What I’d like to do is to apologise to the many people who have had their travel affected… we are very sorry about all the inconvenience.”

Authorities, including London’s Metropolitan Police, stated that the fire is not currently being treated as suspicious, though investigations are ongoing. The London Fire Brigade confirmed that inquiries would focus on the affected electrical distribution equipment.

The incident has sparked frustration among airlines, with industry leaders questioning how such a vital infrastructure could be so vulnerable to a single point of failure.

“You would think they would have significant back-up power,” a senior executive from a major European airline told Reuters.

Woldbye defended the airport’s response, stating that backup systems and contingency procedures functioned as intended. However, he acknowledged that complete prevention of such incidents is not always possible.

“This (power supply) is a bit of a weak point,” he told reporters outside the airport. “But of course, contingencies of certain sizes we cannot guard ourselves against 100% and this is one of them.”

When asked about financial liability, he added, “We don’t have liabilities in place for incidents like this.”

The disruption affected numerous airlines, including British Airways, Virgin Atlantic, American Airlines, Delta Air Lines, JetBlue, Air Canada, Air India, United Airlines, and Qantas, with many flights diverted mid-journey or forced to return to their points of origin. Data from flight analytics firm Cirium showed that shares in multiple airline companies, including major U.S. carriers, dropped following the incident.

Sean Doyle, Chief Executive of British Airways, Heathrow’s largest operator with 341 flights scheduled for Friday, acknowledged the significant challenge of resuming normal operations.

“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. “Unfortunately, it will have a huge impact on all of our customers flying with us over the coming days.”

In response to the crisis, Britain’s Department for Transport temporarily lifted restrictions on overnight flights to help ease congestion.

Travelers affected by the shutdown faced an arduous scramble for alternative arrangements.

“It’s pretty stressful,” said Robyn Autry, a 39-year-old professor who was due to fly home to New York. “I’m worried about how much is it going to cost me to fix this.”

The demand for accommodations surged, with hotel prices near Heathrow skyrocketing. Some booking sites listed rooms for £500 ($645), nearly five times the standard rates.

Industry leaders, electrical engineers, and passengers alike have called for increased scrutiny of Heathrow’s vulnerability to power failures. The airport has suffered other significant outages in recent years, including an automated gate failure and an air traffic control meltdown in 2023.

Philip Ingram, a former intelligence officer in the British military, described the event as a warning sign.

“It is a wake-up call,” he told Reuters. “There is no way that Heathrow should be taken out completely because of a failure in one power substation.”

Willie Walsh, head of the International Air Transport Association (IATA) and former British Airways CEO, criticized Heathrow’s preparedness, stating that the airport had once again failed passengers.

Heathrow officials maintain that their emergency systems, including diesel generators and uninterruptible power supplies, functioned as expected, ensuring safe landings and evacuations. However, they conceded that the airport consumes as much power as a small city, making it impossible to run full operations on backup systems alone.

Meanwhile, the UK government has pledged a thorough review of the incident. A spokesperson for Prime Minister Keir Starmer stated that there were “questions to answer” regarding the airport’s vulnerability to such an outage.

As normal operations resume, airlines and passengers alike brace for the residual impact of Heathrow’s unexpected shutdown, underscoring the need for greater infrastructure resilience in one of the world’s most vital travel hubs.