Heathrow closure: What we know as airport reopens after lengthy closure following substation fire

21 March 2025, 08:34 | Updated: 21 March 2025, 23:33

Heathrow Airport is open again but disruption to flights is expected to continue for some time - here's what we know so far.

What happened?

A fire broke out at an electrical substation in Hayes, west London late on Thursday night.

This caused a power outage at Heathrow, which caused the airport to close for 18 hours.

Thousands of homes were left without power and more than 100 people were evacuated.

Well over 1,000 flights were cancelled.

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

Read more: Heathrow reopens to select flights after 'non-suspicious' blaze as travel chaos sees thousands stranded worldwide

On Friday evening, Heathrow confirmed it would re-open.

It said in a statement: "We’re pleased to say we’re now safely able to begin some flights. Our first flights will be repatriation flights and relocating aircraft. We will now work with the airlines on repatriating the passengers who were diverted to other airports in Europe.

"We hope to run a full operation (on Saturday).  Our priority remains the safety of our passengers and those working at the airport. As the busiest airport in Europe, Heathrow uses as much energy as a small city, therefore getting back to a full and safe operation takes time. We apologise for the inconvenience caused by this incident.”

What should passengers do?

Online flight tracking service FlightRadar24 said the closure would affect more than 1,350 flights to and from Heathrow on Friday. This includes 679 scheduled to land and 678 due to take off from the airport.

It said 120 flights to the airport were in the air when the closure was announced.

Many more departures are expected to take off on Saturday as the airport resumes a normal timetable. British Airways expects to run about 85% of its scheduled flights.

Rory Boland, editor of magazine Which? Travel, said passengers affected by Heathrow's closure were entitled to assistance from their airline.

He said: "If your flight is cancelled you won't be entitled to compensation as these events will be considered an extraordinary circumstance, but you will be entitled to assistance from your airline, including overnight accommodation if needed.

"Passengers will have the choice of being rerouted or accepting a refund, and if you opt for the former your airline is obliged to get you on a new flight as soon as possible, including with rival carriers from alternative airports. If you instead accept a refund, be aware that your airline will have no further duty of care to you and you'll need to make your own arrangements.

"It's also worth checking the terms of your travel insurance to see if you are able to recoup any other expenses you may have incurred as a result of this incident, such as car hire or airport parking fees."

What caused the fire?

While counter-terrorism police are still leading the investigation, the Met say they don't believe it was suspicious. The London Fire Brigade added its focus was on "electrical distribution equipment" as the source.

Earlier on Friday, the government and other MPs had sought to play down speculation of nefarious actors.

Energy Secretary Ed Miliband told LBC there was "no suggestion of foul play".

He said: "We've got to get power restored as quickly as possible and Heathrow opened as quickly as possible.

"But the truth it's going to take time to unwind the disruption for obvious reasons.

"There's no suggestion there is any foul play."

Mr Miliband told us it is more likely to be a "catastrophic accident."

Labour MP Ruth Cadbury also rejected claims something "sinister" may have caused the electrical fire that closed Heathrow Airport.

"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".

What are the knock-on effects?

Travel expert Simon Calder said that the issue would likely stretch into next week.

Mr Calder told LBC: "British Airways is going to take certainly the rest of the weekend and that assumes that things get switched on and everything is running as normally as it can tomorrow.

"I think it will probably go into next week on BA, specifically, maybe Virgin Atlantic as well. For the foreign airlines, it's not so bad because Heathrow isn't such a complete part of their business.

"And so I'm afraid if you're on BA, if you're on Virgin, if you're due to travel anytime in the next three days, I would be prepared to find out that things are going to be disrupted.

"And meanwhile, just remember, air passenger rights rules are on your side. The airline has to get you to your destination as soon as possible. However, that's easier said than done.

"Even when flights come back on, the people who are booked on them take priority and everybody else is going to be scrabbling around for the last few remaining seats."