At least 1,351 flights to and from Heathrow Airport have been delayed, cancelled or diverted today (March 21) after an overnight substation fire caused a huge power outage.

The saga began to unfold when dozens of firefighters began tackling a fire at an electrical substation in west London in the early hours.

Emergency services at the scene in Roseville Road, west London, near to the North Hyde electrical substation which caught fire last night. More than 1,300 flights to and from Heathrow Airport will be disrupted on Friday due to the closure of the airport following the fire. (Image: PA) London Fire Brigade said 10 fire engines and around 70 firefighters were at the blaze on Nestles Avenue, Hayes. Around 20 people have been evacuated from surrounding properties and a 100-metre cordon was put in place as a precaution.

The cause of the fire is not yet known.

Heathrow, Britain's biggest airport, has said 120 flights to the airport were in the air when the closure was announced.

A British Airways flight to London Heathrow was set to take off at 6.15am from Newcastle Airport but has been cancelled.

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

Further flights at 8.45am and 12.15pm have been cancelled - and it is not known when Heathrow will be operational at this stage.

This morning, Energy Secretary Ed Miliband has said has said The Government will be doing everything it can to restore power to Heathrow Airport.

Mr Miliband was asked by Sky News whether a Cobra meeting of senior ministers would be convened to address the matter.

He replied: “I’m sure the Government will be convening in the most appropriate way.

“I’m not going to anticipate the precise form of that, but I’m already in touch with my colleagues on this issue.

Emergency services at the scene in Roseville Road, west London, near to the North Hyde electrical substation which caught fire last night. More than 1,300 flights to and from Heathrow Airport will be disrupted on Friday due to the closure of the airport following the fire. (Image: PA)

“As I say, I’ve spoken to the National Grid, who are really at the epicentre of this, and we will be doing everything we can, both to restore power and help the National Grid.

“To do that, and to ensure that the DfT (Department for Transport), and the Government as a whole, plays its part in, as best we can, minimising the disruption to passengers.”

When asked by Times Radio if she thought the fire at an electricity substation may have been caused intentionally, Labour MP Ruth Cadbury said: “I think that’s somewhat speculative.

“There are obviously questions about it, and I don’t know enough about electricity, but for the airport to be dependent on one substation, it does raise questions.”

She added it was “very, very concerning” that “one substation can close down an airport and there isn’t an alternative source of energy”.