London’s Heathrow Airport closed Friday local time and will remain closed all day after a fire at a nearby electricity substation caused power outages at the major transportation center, NBC News reported. “Whilst fire crews are responding to the incident, we do not have clarity on when power may be reliably restored,” the airport said in a statement early Friday local time. “To maintain the safety of our passengers and colleagues, we have no choice but to close Heathrow until 23h59 on 21 March 2025,” the airport said. The airport said that it expects “significant disruption over the coming days” and that it would notify the public as more becomes known. Passengers should not go to the airport until it is reopened, it said. “We know this will be disappointing for passengers and we want to reassure that we are working as hard as possible to resolve the situation,” the airport said. A video posted on social media showed the inside of the airport with only emergency lighting. Passengers should not go to the airport until it is reopened, it said. “We know this will be disappointing for passengers and we want to reassure that we are working as hard as possible to resolve the situation,” the airport said. Six airports serve London, but Heathrow is the biggest. It predicts 84.2 million passengers will travel through the airport this year. The London Fire Brigade said that a transformer in a substation in Hayes, which is north of Heathrow, was on fire and that 150 people have been evacuated. “This is a highly visible and significant incident, and our firefighters are working tirelessly in challenging conditions to bring the fire under control as swiftly as possible,” Fire Assistant Commissioner Pat Goulbourne said in a statement. The fire has caused power outages at “a large number of homes and local businesses,” Goulbourne said, and there was heavy smoke. The cause of the fire was not known, the Fire Brigade said. The Fire Brigade was called at 11:23 p.m. Thursday local time (7:23 p.m. ET), the firefighting agency said. Crews remain at the scene of the fire in #Hayes – please continue to keep windows & doors closed due to smoke & avoid the area. This will be a prolonged incident, with crews remaining on scene throughout the night.Read more: https://t.co/d6UNReGHa6 pic.twitter.com/6rQpIp5Bad— London Fire Brigade (@LondonFire) March 21, 2025 “This will be a prolonged incident,” Goulbourne said. The disruption is expected to continue Friday morning, and the public was urged to avoid the area. Flight tracking site FlightRadar24 said Friday morning local time that, “There are currently 120 aircraft in the air that will be diverting to alternate airports or returning to their origins.” In 2021, Heathrow celebrated its 75th anniversary since it became a commercial airport. Before that, it was a Royal Air Force airfield during World War II. Jean Lee contributed. This article first appeared on NBCNews.com. Read more from NBC News here: Georgetown, Columbia and Brown scholars targeted for deportation by Trump administration Florida man faces execution for the killing of an 8-year-old girl and her grandmother Maryland officials failed to assess vulnerability of Francis Scott Key Bridge before collapse, NTSB says ...read more read less