London's Heathrow Airport was closed today and was flights expected to be grounded for at least the rest of Friday, after a fire at a nearby electrical substation caused a massive power outage at the major transportation center.
While the fire had been almost entirely extinguished by late morning local time on Friday, more than 1,300 flights and 200,000 passengers were affected by the closure, with disruption expected to last into the weekend and travelers left stranded in the U.K and around the world as they scrambled to make alternate plans.
"We do not have clarity on when power may be reliably restored," the airport said in a statement early Friday local time, adding that Heathrow's doors would remain closed until at least the end of the day.
Six airports serve London, but Heathrow is the biggest, with the international hub predicting that at least 84.2 million passengers will travel through the airport this year.
The airport has also previously been described as the "most connected" in the world, with New York and Los Angeles among the top destinations for Heathrow passengers.
British Energy Secretary Ed Miliband told BBC News that the situation was "unprecedented" after the fire also affected a backup generator at the power substation.
The closure caused widespread confusion and chaos for travelers in London and around the globe, with many posting on social media after being temporarily stranded at airports across the world after their flights were canceled.
The disruption was expected to impact at least 1,351 flights set to arrive at or depart from Heathrow on Friday, according to FlightRadar24. The flight tracking website said that figure didn't include flights that might be canceled or delayed because of aircraft being "out of position."
FlightAware's real-time flight tracker, meanwhile, showed that at least 170 flights scheduled to depart from Heathrow had been canceled as of early Friday morning, along with 145 flights expected to land there. Those numbers were expected to grow, however.
The airport said that it also expected "significant disruption over the coming days" and that it would notify the public as more became known as it urged passengers not to go to the site until it reopened.
“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.
One of those disappointed passengers was Los Angeles-based comedian and star of "Adam Ruins Everything" Adam Conover, who was in transit to London for a stand-up gig when his flight was diverted midair.
“We were in the air for about it 90 minutes and they had just finished dinner service,” the 42-year-old comedian told NBC News in a phone interview Friday morning. “Then the captain came on and said there was a fire … we had to turn around.”
After a brief nap, the creator of Netflix's "The G Word" said he’ll be flying to New York’s John F. Kennedy International Airport, where he faces a four-hour layover, a flight to Manchester, and then an at least two-hour-long train to the British capital.
A video posted on social media showed the inside of the airport with only emergency lighting.
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. It said it was called to the scene just after 11:20 p.m. Thursday local time (7:20 p.m. ET).
“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. “This will be a prolonged incident,” Goulbourne said.
As of early Friday morning, National Grid U.K. said in a post on X that at least 4,900 customers were without electricity as it worked to restore power to the affected areas.
National Air Traffic Services, or NATS, the U.K.'s leading provider of air traffic control services, said it was working closely with Heathrow and airlines to manage the disruption caused by the sudden closure.
“We have well-rehearsed plans in place which includes a requirement for aircraft to either turn back or divert to a non-U.K. airport, as well as stopping other flights at their point of departure," it said.
NATS added that this was part of the aviation industry "mass diversion plan" and that it had been made clear to airlines that there was a limited capacity at other British airports to accommodate diversions.
British Airways, which is based at Heathrow, appeared to be the airline most affected by the closures, with at least 124 flights affected as of early Friday morning, according to data published by FlightAware.
In a statement, an airline spokesperson said the closures had a "significant impact on our operation." It said that where possible, it had been redirecting inbound flights already on their way to Heathrow to other airports in the U.K.
As of early Friday, other British airports were not yet heavily impacted yet by the changes, with a spokesperson for London Luton Airport saying its operations had not been affected.
Meanwhile, operations at London Stansted Airport appeared to be running smoothly.
"Departures here are no busier than normal this morning. If anything, security was actually faster than normal," NBC News Social Media Editor Fiona Day said.
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.
Chantal Da Silva and Zoe Holland reported from London and Phil Helsel reported from Los Angeles.
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