“Due to a fire at an electrical substation supplying the airport, Heathrow is experiencing a significant power outage,” it said in a post on X. “To maintain the safety of our passengers and colleagues, Heathrow will be closed until (11:59 p.m. Friday local time). Passengers are advised not to travel to the airport and should contact their airline for further information. We apologise for the inconvenience.”
It was unclear exactly how many flights were being impacted.
Britain’s National Rail service cancelled service to and from Heathrow for the day.
The London Fire Brigade said 10 fire engines and around 70 firefighters were tackling the blaze at a substation near the airport in the west London town of Hayes. Its cause wasn’t immediately known. It started late Thursday night.
“This will be a prolonged incident, with crews remaining on scene throughout the night,” the brigade said.
The fire was “producing a significant amount of smoke. Please keep your windows and doors closed and avoid the area where possible,” the brigade said.
The power outage was “affecting a large number of homes and local businesses, and we are working closely with our partners to minimise disruption,” Assistant Commissioner Pat Goulbourne said in a statement in which he described the fire as “highly visible and significant.”
Goulbourne said firefighters had led 29 people to safety from nearby properties, and around 150 people evacuated.
Scottish and Southern Electricity Networks said in a post on X the power outage affected more than 16,300 homes, according to The Associated Press.
According to the latest numbers from travel data provider OAG Aviation, Heathrow is the fifth busiest airport in the world.
It is Britain’s busiest.