National Express has suspended all services to London Heathrow following the closure of the airport due to a substation fire – but services to London Gatwick will operate as normal.

Heathrow Airport will be closed all day after a major fire at a nearby electrical substation.

The airport has issued a statement on X explaining that it is experiencing a “significant power outage”.

Because the substation, in Nestles Avenue, Hayes, supplies the airport, Heathrow will be shut until 11.59pm tonight “to maintain the safety of our passengers and colleagues”.

A fire in a transformer in Nestles Avenue, Hayes, west London, which means Heathrow will be closed all day on Friday, March 21. Picture courtesy of London Fire Brigade

placeholder image — A fire in a transformer in Nestles Avenue, Hayes, west London, which means Heathrow will be closed all day on Friday, March 21. Picture courtesy of London Fire Brigade

The statement ends: “Passengers are advised not to travel to the airport and should contact their airline for further information. We apologise for the inconvenience.”

And following the closure of London Heathrow Airport, National Express has suspended all services to the airport until 11.59pm this evening (March 21).

Customers are advised not to travel to the airport today.

Services to London Gatwick Airport, London Stansted Airport and London Luton Airport will operate as normal.

National Express is proactively contacting customers who have already booked to travel to London Heathrow Airport today and is offering free amendments for those who are affected.

More information is available at www.nationalexpress.com.

A spokesperson for National Express said: “All services to and from London Heathrow Airport are suspended until 23:59 and we are proactively contacting customers due to travel today for a free ticket amendment.

“Customers are advised to check our website and social media channels for the latest updates.

“We apologise for the inconvenience.”

The fire started at about 11.20pm last night. London Fire Brigade sent about 70 firefighters on 10 fire engines.

The fire service was called at 11.23pm and crews from Hayes, Heathrow, Hillingdon, Southall and surrounding fire stations were sent to the scene.

The cause of the fire is not yet known.

At 5.50am the transformer in the substation was still alight.

Online flight tracking service FlightRadar24 said the closure would affect at least 1,351 flights to and from Heathrow, saying 120 flights to the airport were in the air when the closure was announced.

Online tracking services showed flights being diverted to Gatwick, Charles de Gaulle Airport in Paris and Ireland’s Shannon Airport, as well as airports in the United States and Canada.

Heathrow is the UK’s largest airport, with more than 83.9 million passengers travelling through its terminals in 2024.