London’s Heathrow Airport announces complete shutdown due to power outage

The closure of Heathrow Airport has caused massive travel disruptions, with hundreds of flights coming from across the globe forced to divert midair.

“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,” says in X.

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… pic.twitter.com/7SWNJP8ojd

— Heathrow Airport (@HeathrowAirport) March 21, 2025

Some more details from Flightradar24, which says that more than 1,000 flights will be impacted by the sudden closure of Heathrow today.

“Today’s total closure of London-Heathrow will affect at least 1,351 flights to/from LHR,” the flight tracker said in a post on Bluesky, “That doesn’t include any flights that might be cancelled or delayed due to aircraft being out of position.”

Today’s total closure of London-Heathrow will affect at least 1,351 flights to/from LHR.

That doesn’t include any flights that might be canceled or delayed due to aircraft being out of position.

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— Flightradar24 (@flightradar24.com) 21 March 2025 at 04:02

Flight diversions

The sudden closure has caused a ripple effect across global aviation networks. Flights en route to Heathrow have been diverted mid-air to various airports. For instance, Qantas Airways redirected its flight from Perth to Paris, while a United Airlines flight from New York was diverted to Shannon, Ireland. Some flights from the United States turned around mid-flight to return to their departure points. British Airways and Virgin Atlantic have rerouted flights to nearby Gatwick Airport.

Beyond the airport, the fire has had significant local repercussions. The London Fire Brigade reported evacuating 29 people from nearby properties as a precautionary measure. Residents in the vicinity have been advised to keep windows and doors closed due to smoke, and a 200-meter safety cordon has been established around the affected area. ​

🚨 BREAKING: Heathrow Airport says it will be closed all day due to significant power outage caused by a fire at a nearby electrical substation

“We expect significant disruption over the coming days and passengers should not travel to the airport under any circumstances” pic.twitter.com/jeqEqb8BX6

— Politics UK (@PolitlcsUK) March 21, 2025

UK Energy Secretary Ed Miliband described the incident as “catastrophic,” highlighting the severity of the situation. He emphasized the need to understand the cause and strengthen infrastructure resilience to prevent future occurrences. The London Fire Brigade has since brought the fire under control and is conducting investigations to determine the exact cause. ​

#WATCH Britain’s Energy Secretary Ed Miliband said the substation fire that caused Heathrow’s shutdown also affected its backup power supply. The closure has disrupted global travel, canceling, delaying, or diverting hundreds of flights, while experts questioned the lack of a… pic.twitter.com/s4pzVKwSHJ

— 凤凰欧洲 PhoenixCNE News (@PhoenixCNE_News) March 21, 2025

Advice to passengers

Passengers scheduled to travel through Heathrow are strongly advised not to proceed to the airport and to contact their respective airlines for the latest information and alternative arrangements. Given the scale of the disruption, it is anticipated that normal operations may take several days to resume fully.​

This incident underscores the vulnerability of critical infrastructure and the cascading effects such events can have on global transportation networks. Authorities and stakeholders are working diligently to restore services and assist affected passengers during this challenging time.

Officers continue to support @LondonFire following a fire at an electrical substation in Hayes.@HeathrowAirport is closed and passengers are advised not to travel to the airport on Friday. https://t.co/zpL7zWQMEW

— Metropolitan Police (@metpoliceuk) March 21, 2025

“The fire is now under control”

“The fire in Hayes is now under control, but we will remain on the scene throughout the day. Our fire investigators will begin their investigation & we will continue working closely with our partners to minimise disruption and support the community,” said London Fire Brigade in X.

The fire in #Hayes is now under control, but we will remain on scene throughout the day.

Our fire investigators will begin their investigation & we will continue working closely with our partners to minimise disruption and support the community https://t.co/IrOHNJTpqp pic.twitter.com/AnRe5whtfE

— London Fire Brigade (@LondonFire) March 21, 2025

“I remain in close contact with emergency services and am grateful for their swift response overnight. Road closures remain in place and Londoners are being asked to avoid the area wherever possible,” said Mayor of London, Sadiq Khan.