Flightmares for hundreds of thousands after Heathrow all-day closure sparks travel chaos

• Heathrow Airport will be closed all day Friday after a nearby fire caused a power outage.
• Heathrow is advising passengers not to travel to the airport and to contact their airlines.
• More than 1,300 flights are expected to be affected.

London's Heathrow Airport, one of the world's busiest, will be closed through Friday after a large fire nearby caused a "significant power outage."

Flightradar24, a live flight-tracking platform, told Business Insider that 120 flights already in the air were expected to be diverted. The platform said at least 1,351 flights would be affected.

Heathrow advised passengers not to travel to the airport, and to contact their airline for more information.

Last year, about 83.9 million people flew through Heathrow, up 6% from the previous year. The airport says it welcomes over 200,000 passengers a day.

Heathrow was the fourth busiest airport in the world in 2024, according to OAG, a travel data company, behind only Tokyo Haneda Airport, Dubai International Airport, and Hartsfield-Jackson Atlanta International Airport.

"Due to a fire at an electrical substation supplying the airport, Heathrow is experiencing a significant power outage," the airport posted to X early Friday morning local time.

"To maintain the safety of our passengers and colleagues, Heathrow will be closed until 23h59 on 21 March."

A spokesperson for British Airways, one of the airport's main airlines, said in a statement to BI that this would "have a significant impact on our operation and our customers."

"We're working as quickly as possible to update them on their travel options for the next 24 hours and beyond," they added.

The airline said it was redirecting flights already on their way to Heathrow to other UK airports.

A spokesperson for Virgin Atlantic, whose main UK hub is Heathrow, told BI that the closure was having a "significant impact" on its flight operations to and from the airport. They also advised customers not to travel to Heathrow.

"We're incredibly sorry for the disruption this will cause and are working with our teams to ensure customers can complete their journeys as quickly as possible," the spokesperson said.

Qatar Airways, in an X post, said that the closure had affected five flights from London to Doha and four flights from Doha to London.

"Passengers impacted due to above will be taken care of by our customer care and airport teams," it added.

The fire occurred at an electricity substation in Hayes in West London, about 1.5 miles from the airport. The cause of the fire is not yet known.

The London Fire Brigade said in a post on X that 10 fire engines and about 70 firefighters were called to the scene.

Images show large flames and plumes of thick black smoke. Local media reported that tens of thousands of homes in the area are without power.

Around 150 people have been evacuated so far and a 200-meter cordon is in place, the London Fire Brigade said.

"This will be a prolonged incident, with crews remaining on scene throughout the night," it said on its website. "As we head into the morning, disruption is expected to increase, and we urge people to avoid the area wherever possible."

Sadiq Khan, the mayor of London, said in a statement that electricity suppliers are working hard to restore power, but that Heathrow said it will be closed "all day and has warned of significant disruption over the coming days."

London has several other international airports including Gatwick, the city's second-busiest airport, and Stansted, known for budget flights and flights to Europe.

Do you have a story to share about how your plans are affected by Heathrow's shutdown? Contact reporter Pete Syme at psyme@businessinsider.com.