Heathrow Airport has reopened for a limited number of flights after a large fire at a nearby electrical substation disrupted travel for around 200,000 passengers.
Counter-terror police were leading the investigation into the cause of the blaze, which triggered a “significant power outage” that led to more than 1,000 flights to and from the airport being cancelled.
Heathrow’s boss apologised to passengers, describing the disruption “as big as it gets for our airport” and admitting “we cannot guard ourselves 100%”.
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In an update on Friday evening, the Metropolitan Police said the cause of the fire is believed to be non-suspicious, while the London Fire Brigade (LFB) announced its investigation will focus on the electrical distribution equipment.
Heathrow is expected to run a full schedule on Saturday.
Image: The proximity of Heathrow to the electrical substation
The fire that caused the power outage is at the North Hyde substation in Hayes, about 1.5 miles to the north of the west London airport.
LFB received the first reports of the fire at 11.23pm on Thursday.
Heathrow initially announced the airport would be closed until 11.59pm on Friday but later said repatriation flights for passengers diverted to other airports in Europe would resume on Friday evening.
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0:43 Heathrow outage nearly ‘as big as it gets’
Several airlines announced they would restart scheduled flights both to and from Heathrow, including British Airways (BA), Air Canada and United Airlines.
A BA flight to Riyadh, in Saudi Arabia, took off just before 9pm after a slight delay to its expected departure time.
Restrictions on overnight flights have also been temporarily lifted to help ease congestion, the Department of Transport said.
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0:53 Runways deserted as substation fire is put out 
Image: Flightradar24 showed up to 120 planes in the air would be forced to divert or turn back. Pic: Flightradar24/X
Airport disruption nearly ‘as big as it gets’
Heathrow Airport’s chief executive Thomas Woldbye told reporters the flights taking off on Friday evening would help make sure the airport has “operations in place” for Saturday morning.
He continued: “Tomorrow morning we expect to be back in full operation, so 100% operation as a normal day.”
Image: Passengers arrive at Heathrow Airport as flights resume. Pic: AP
Mr Woldbye added that passengers who were planning to fly from Heathrow on Saturday should arrive at the airport in time for their flight as normal.
The chief executive also apologised to the passengers whose journeys had been disrupted but said he would not have closed down the airport unless there were “severe safety concerns”.
Image: The height of the fire was described as ‘absolutely apocalyptic’. @JoselynEMuirhe1/X/PA 
Image: Pic: AP
Asked whether the disruption caused by the fire suggested there was a “weak point” in Heathrow’s operations, Mr Woldbye replied: “We can’t guard ourselves 100%. This has been a major incident.
“Short of anybody getting hurt, this is as big as it gets for our airport and we are actually coming back quite fast.”
He added: “This is unprecedented, it’s never happened before.”
It comes after Number 10 said earlier that there are questions to be answered about how the fire has caused so much chaos.
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Image: Stranded passengers at Heathrow Terminal 5. Pic: PA 
Image: Pic: PA
Mr Woldbye said: “Our procedures have worked the way they should… Of course the prime minister should ask questions and we’ll be happy to answer them.”
Earlier, the airport said it expected “significant disruption over the coming days” and warned passengers “not travel to the airport under any circumstances until the airport reopens”. All trains to Heathrow were suspended.
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0:21 Moment Heathrow substation ignites
Some power has returned to Terminal 4, with lights in the main building and lifts in the multi-storey car park operational again.
The disruption began late on Thursday night when fire crews were called to a blaze in west London at an electricity substation serving Heathrow and local properties.
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0:40 ‘It’s all dark here, mate’: Fire cuts Heathrow power
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Thousands of passengers stranded
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.
The figure, from the Civil Aviation Authority, is equivalent to about 229,000 passengers using the hub every day.
Aviation analytics firm Cirium told the New York Times that it believed as many as 290,000 passengers could have been affected on Friday – enough to fill Wembley Stadium three times.
Image: Smoke was continuing to rise above the North Hyde electrical substation this afternoon. Pic: PA 
Image: Pools of what looks like foam surround the damaged substation. Pic: PA
Oil fire still alight at substation
LFB deputy commissioner Jonathan Smith told reporters at a news conference the fire involved a transformer – a key part of the substation – with 25,000 litres of cooling oil “fully alight”.
Image: Fire crews said the blaze was now under control. Pic: PA 
Image: Aerial footage shows the scale of the damage the fire has done to the substation
Crews evacuated 29 people from neighbouring properties but there were no casualties.
In all, 67,000 households were left without power after the fire at the substation, but all supplies have been restored.
Earlier LFB said 10 engines and around 70 firefighters had been working to extinguish the blaze.
Pictures from the scene showed large flames and plumes of thick black smoke.
The LFB said in a statement that 5% of the fire was still alight as of 7pm on Friday.
