Emergency services were called to a power substation in Nestles Avenue, Hayes, around 11.30pm yesterday (March 20) after the transformer caught light.
The fire service finally brought the fire under control eight hours later around 7.45am the next day.
There were no injuries but 29 people were evacuated from nearby properties and 150 people evacuated within a 200-metre cordon.
A nearby resident said she heard a “massive explosion” just before midnight.
@BBCLondonNews There’s a huge fire in Hayes – London, looks like North Hyde Electricity sub station pic.twitter.com/PJNpbHjZxu
— Vil (@fire_at_Vill) March 20, 2025
All the power went off, she said, adding that she could see a “massive fire” through a front window.
“It just smelled like burning,” she said, adding that it was difficult to work out where exactly the fire was.
Another local resident, Mathew Muirhead, was working a night shift on Thursday when he noticed smoke rising from the electrical substation.
“We were stood outside our branch in Hayes and my colleague noticed smoke coming over the trees,” the 42-year-old told reporters.
“It was 23.30 when we saw it, we were heading to West Drayton, so we went to check it out, we heard the sirens as we were headed to Bulls Bridge roundabout.
“We saw a bright flash of white and all the lights in town went out.
“My wife rang me and told me our electric was out – I found out a few hours later that Heathrow was completely shut down.”
Assistant Commissioner Pat Goulbourne said: “This was a very visible and significant incident, and our firefighters worked tirelessly in challenging conditions to bring the fire under control as swiftly as possible.
“Thanks to their efforts and co-ordinated multi-agency response, we successfully contained the fire and prevented further spread.
“We will maintain a presence at the scene throughout the day, assisting the National Grid as they assess the site.
“The fire has caused a widespread power outage, affecting many homes, local businesses and Heathrow Airport.
“While power has been restored to some properties, we continue to work closely with our partners to minimise disruption.
“Firefighters safely evacuated 29 people from neighbouring properties and, as a precaution, a 200-metre cordon was established, with around 150 people evacuated.
“Due to the significant smoke, we strongly advise local residents to keep their windows and doors closed, as some smoke will remain for a number of hours today.
“Scientific advisers will also be on-site this morning to conduct further assessments and monitor the air quality.”
Energy Secretary Ed Miliband said that the National Grid had told him they had not seen “anything like the scale” of what happened with the “seriousness” of the fire.
Heathrow Airport will be closed until midnight on March 21, it announced, with flights cancelled or redirected.
At least 1,351 flights to and from the airport will be affected, online flight tracking service FlightRadar24 said.
120 flights to the airport were in the air when the closure was announced.
Heathrow is the UK’s largest airport with 83.9 million passengers passing through in 2024.
