The Met Police has said there appear to be ‘no suspicious circumstances’ surrounding the fire at an electricity sub-station that led to the closure of Heathrow Airport in a major update in its investigation.
The force’s Counter Terrorism Command had been leading the investigation to establish the cause of the blaze at the substation in Hayes, London, on Friday March 21.
In an update on Tuesday, the Met said officers had found ‘no evidence to suggest that the incident was suspicious in nature’.
‘As such, we are no longer treating this as a potentially criminal matter,’ the force added.
The cause of the fire will continue to be investigated by National Grid, London Fire Brigade and Southern Electricity Network.
The fire led to the closure of Heathrow for almost an entire day, leaving hundreds of thousands of passengers stranded and travel chaos around the world.
Thousands of west London homes were also left without power following the incident.
It comes as it was confirmed that the airport’s boss, Tomas Woldbye, will be grilled by MPs on the closure next month.
The Met Police has said there appear to be ‘no suspicious circumstances’ surrounding the fire at an electricity sub-station that led to the closure of Heathrow Airport
Stranded passengers are pictured at Heathrow Airport on Friday as they awaited updates on the fire
The fire in Hayes, west London, led to the closure of Heathrow and thousands of homes went without power
Firefighters are seen tackling the blaze at the electricity substation on Friday
A statement from the Met Police read: ‘The Met’s Counter Terrorism Command has been working with partners to establish the cause of the fire at the electricity sub-station in Hayes last week (21 March).
‘Following enquiries to date, officers have found no evidence to suggest that the incident was suspicious in nature.
‘As such, we are no longer treating this as a potentially criminal matter, although we continue to support other partners, including colleagues from National Grid, London Fire Brigade and SSEN, with whom we remain in close contact.
‘Should any relevant new information or evidence come to light it will be looked at and considered as appropriate.’
More than 70 firefighters and 10 fire engines rushed to the scene, on Nestles Avenue in Hayes, to tackle the blaze on Thursday evening.
Some 150 people were evacuated and a 200-metre cordon put in place, such was the scale and threat of the blaze.
In addition at least 16,300 homes went without power due to the damage caused by the fire, which broke out at around 11.30pm on Thursday night.
Around 220,000 people were due to travel through Heathrow on Friday and the chaos from the closure rumbled on over the weekend.
The cause of the fire will continue to be investigated by National Grid, London Fire Brigade and Southern Electricity Network
The fire led to the closure of Heathrow for almost an entire day, leaving hundreds of thousands of passengers stranded and travel chaos around the world
Small amounts of smoke could still be seen rising from the sub-station on Tuesday morning
Parts of the Hayes sub-station are now little more than charred remains
After initially briefing the airport would be shut for at least 24 hours, bosses were able to reopen to some flights by Friday evening.
It was the biggest disruption for UK aviation since the Icelandic volcanic ash cloud grounded and diverted flights in April and May 2010.
Heathrow is one of the world’s busiest airports for international travel, and the biggest in Europe. It had its busiest January on record earlier this year, with more than 6.3 million passengers, up more than 5 per cent for the same period last year.
January also was the 11th month in a row it averaged over 200,000 passengers a day, with the airport citing transatlantic travel as a key contributor.
Witnesses to the outbreak of the fire said they heard an ‘explosion’ before seeing billowing smoke and flames licking up into the sky.
The Met confirmed after the outbreak of the fire that counter-terror police would lead the investigation ‘as a precaution’ – although the force has now stood these officers down.
The cause of the fire has not been confirmed by police.
New photos taken today showed tiny amounts of smoke still coming from the wrecked sub-station, which is now little more than charred remains.
The blaze, which broke out at around 11:30pm on Thursday, could be seen for miles
A huge fireball was seen in the sky as the sub-station erupted into flames on Thursday night
The London Fire Brigade also confirmed today that it has taken charge of the investigation from the Met.
Commenting on the incident, London Fire Brigade Deputy Commissioner Jonathan Smith said: ‘At 23:23 on the evening of 20 March, London Fire Brigade received the first of 212 calls to a fire in a high voltage substation near Heathrow Airport.
‘The fire involved a transformer comprising 25,000 litres of its cooling oil fully alight. This created a major hazard owing to the still live high voltage equipment and the nature of an oil fuelled fire.
‘The first appliance was on scene within five minutes of mobilisation. The Brigade was in close contact with blue light partners overnight, and at 00:42 the Met police declared a major incident.
‘Ten fire engines, two Bulk Foam Units and one High Volume Pump were on scene at the peak of the incident – this equates to approximately 70 London Fire Brigade personnel.
‘Our firefighters worked tirelessly in challenging and hazardous conditions overnight to bring the fire under control as swiftly as possible.
‘Firefighters safely evacuated 29 people from neighbouring properties, and as a precaution, a 200-metre cordon was established. Working with the Met police, around 150 people were evacuated to a rest centre. The majority of those people have been able to return to their homes.
‘I would like to take this opportunity to thank Firefighters and Control officers for their courage and professionalism in bringing this incident under control in what were very challenging circumstances.’
The LFB said it will maintain a small presence on scene for the coming days to ensure any remaining hot-spots within the electrical equipment are fully extinguished.
Following the shock closure, which has led to questions about the capabilities of Heathrow’s back-up power systems, it was confirmed MPs would have the opportunity to grill the airport’s CEO, Thomas Woldbye, over the incident.
He will appear before the Transport Select Committee at a one-off session on Wednesday, April 2.
This is a breaking news story and is being updated.