London’s Heathrow Airport, one the world’s busiest airports, will be closed all day Friday due to a “significant power outage” caused by a fire at a nearby electrical substation.

“Whilst fire crews are responding to the incident, we do not have clarity on when power may be reliably restored. To maintain the safety of our passengers and colleagues, we made the decision to close Heathrow until 23h59 on 21 March 2025,” an airport spokesperson told Fox News.

“We expect significant disruption over the coming days and passengers should not travel to the airport under any circumstances until the airport reopens,” the spokesperson added.

🚨Just in: London Heathrow Airport will be closed all day tomorrow due to a 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/LpeBVM6Hws

— The Calvin Coolidge Project (@TheCalvinCooli1) March 21, 2025

The outage has already disrupted approximately 1,300 flights in and out of Heathrow.

More than 1,300 flights to and from London’s Heathrow airport have been cancelled after its power was cut by a fire at a nearby electricity substation, causing turmoil for travellers.

Follow our live blog for updates: https://t.co/Fce9p0qXBY pic.twitter.com/9BvDNkYSCA

— Financial Times (@FT) March 21, 2025

Fox Business reports:

The airport was anticipating up to 291,000 passengers on a total of 1,351 flights on Friday, Reuters reported.

Passengers have been told to contact their individual airline for further details on new flight times.

Airlines began issuing statements on Friday addressing how the 24-hour closure would impact their passengers and flights to and from the airport.

British Airways said the disruption “will clearly have a significant impact on our operation and our customers and we’re working as quickly as possible to update them on their travel options for the next 24 hours and beyond.”

A United Airlines spokesperson told FOX Business that “Following the closure, seven United flights returned to their origin or to other airports, and Friday flights to London Heathrow have been canceled.

“We are continuing to work with our customers to offer alternative travel options,” the spokesperson added.

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

According to Sky News, counter-terrorism police are among the agencies investigating the fire.

WATCH:

BREAKING: Sky News understands counter-terrorism police are involved in the investigation into the fire at the North Hyde substation.

It's understood it is one of a number of departments that are part of the inquiry, which is normal practice for an incident of this scale. pic.twitter.com/ExaJkcNpId

— Sky News (@SkyNews) March 21, 2025

Per Sky News:

Planes usually begin landing and taking off at around 5am after the regular overnight quiet period.

Around 120 flights were bound for Heathrow when the airport announced it would be closing for the day. Some were turned around while others were diverted to other airports in the UK and Europe.

Flightradar24 estimates 1,357 flights would be affected today, including around 120 which were already in the air this morning before the shutdown.

Data from the tracking site also showed Amsterdam took the most diversions at seven, while Gatwick, Frankfurt and Shannon all took six flights each.

Heathrow is one of the world’s busiest airports and had a record 83.9 million passengers last year, with a plane landing or taking off around every 45 seconds.