One of the world’s largest airports is closed.

Heathrow Airport in London has been shut down all day following a devastating electrical fire, triggering massive power outages and plunging the travel industry into chaos.

With hundreds of thousands of passengers affected, experts warn the disruption could last for days, causing ripple effects across the globe.

Electrical substation exploded

During the early hours of Friday, a shocking announcement was posted on Heathrow’s official X account:

”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 and should contact their airline for further information. We apologise for the inconvenience.”

A Heathrow spokesperson also told British media that flight disruptions are expected to last for several days.

There is no fire at Heathrow itself, but a nearby blaze has disrupted operations to the point that the airport cannot remain open. According to Sky News, the fire started in a transformer building in Hayes, roughly two kilometers (1.2 miles) from Heathrow. The airport’s main electrical substation exploded, causing the severe power outage.

Around 200,000 passengers were set to travel through Heathrow today, but the airport’s closure has sparked major disruption that will likely continue into the weekend and beyond.

The fire started around 11:30 PM Thursday night, and although firefighters worked through the night to control it, part of the transformer building is still burning. Police have declared a major incident, and investigators are looking into the cause.

By morning, the fire had been extinguished, but specialist firefighters were still working to dampen the area using breathing apparatus.

”This was a very visible and significant incident, and our firefighters worked tirelessly in challenging conditions to bring the fire under control as swiftly as possible,” assistant commissioner Pat Goulbourne said.

The decision to shut down the airport due to the failure of one substation raises serious concerns. While Heathrow officials have confirmed that backup power systems are in place, activating these contingencies takes time and is not an immediate fix.

According to Daily Mail, at least 1,357 flights have been canceled, diverted, or delayed. Some flights that were already en route to London have landed at other airports, but many, including Gatwick, are now at full capacity.

As the chaos continues, other European airports are bracing for an influx of planes that are too far into their flights to turn back and must now be rerouted.

Heathrow, one of the world’s busiest airports for international travel, had a record-breaking January this year, welcoming over 6.3 million passengers—an increase of more than 5% compared to the same time last year. It was also the 11th consecutive month the airport handled an average of over 200,000 passengers per day, with transatlantic flights playing a key role in the surge.

In addition to the flight disruptions, rail services to and from Heathrow have been canceled for Friday, according to National Rail.