London, Mar. 22: Flights at London’s Heathrow Airport slowly resumed after a fire at an electrical substation caused a major power outage, forcing Europe’s busiest airport to shut down for about 18 hours. The disruption led to widespread cancellations and delays, affecting around 200,000 passengers.

The fire broke out just before midnight on Thursday at a substation about 3.2 km from the airport. It took firefighters nearly seven hours to bring it under control. The London Fire Brigade is investigating the electrical equipment at the substation, but authorities have found no signs of foul play.

The fire cut power to thousands of homes in the area and affected at least 1,350 flights, according to flight tracking service FlightRadar24. The impact is expected to last for days as airlines rearrange flights and passengers try to rebook their trips.

After power was restored, Heathrow lifted its closure order, and a British Airways flight landed just before sunset on Friday. Later, a British Airways flight to Riyadh, Saudi Arabia, became one of the first to depart. The airport expects to operate a full schedule by Saturday.

Some passengers experienced unexpected detours. Lawrence Hayes, flying from New York to London with Virgin Atlantic, found himself diverted to Glasgow. “It was a red-eye flight, and I’d already had a full day, so I don’t even know how long I’ve been up for,” he told the BBC.

Many flights were forced to land elsewhere, including Gatwick Airport, Charles de Gaulle Airport in Paris, and Shannon Airport in Ireland.

Some residents in west London reported hearing an explosion and seeing a fireball before the blackout. The London Fire Brigade sent ten fire engines and 70 firefighters to tackle the flames. The fire also left 67,000 homes without electricity, though most had power restored by morning.

Despite having a backup power system, Heathrow was unable to keep the airport running. “Contingencies of certain sizes we cannot guard ourselves against 100 per cent, and this is one of them,” said Heathrow’s CEO, Thomas Woldbye.

The disruption has sparked criticism over the UK’s infrastructure readiness. Alan Mendoza of the Henry Jackson Society, a security think tank, said, “The UK’s critical national infrastructure is not sufficiently hardened for anywhere near the level it would need to be at to give us confidence this won’t happen again”, as reported by AP.

Prime Minister Keir Starmer’s spokesperson, Tom Wells, acknowledged the concerns and called for a thorough investigation to prevent a repeat of such disruption.

For many passengers, the shutdown caused confusion and inconvenience. Mark Doherty, traveling from New York’s JFK Airport, was halfway across the Atlantic when he noticed on the inflight map that his plane was turning around. “I was like, you’re joking,” he said. The flight ended up returning to New York.

At Heathrow, Andrea Sri had brought her brother, sister-in-law, and their three children to catch a flight to Dallas, but they found out upon arrival that it had been cancelled. “It was a waste of time. Very confusing,” she said. She tried contacting British Airways but was told their phone lines wouldn’t open until 8 am.

Airlines scrambled to find solutions. Qantas redirected flights from Singapore and Perth to Paris and arranged for passengers to travel to London by bus and train.

By Friday night, flights had started landing and taking off again, though delays are expected to continue for several days.

For locals near Heathrow, the unusual quiet was noticeable. “Living near Heathrow is noisy – there are planes every 90 seconds or so, plus the constant hum of traffic – but you get used to it, to the point of no longer noticing,” said James Henderson, a resident of over 20 years. “Today is different, you can hear the birds singing.”-Agencies