London's Heathrow Airport will be closed throughout Friday due to a "significant" electrical outage.
Heathrow is the largest airport in the UK, and one of the largest in the world. According to Flight Radar, the closure will affect nearly 1,000 flights. Passengers are advised to contact their airlines.
In a post on X, Heathrow said: "Due to a fire at an electrical substation supplying the airport, Heathrow is experiencing a significant power outage."
"To maintain the safety of our passengers and colleagues, Heathrow will be closed until 23h59 on 21 March. Passengers are advised not to travel to the airport and should contact their airline for further information. We apologise for the inconvenience."
The fire broke out Thursday night at 11:30 p.m. After several hours of firefighting, the fire was still not contained, and at 2:00a.m. Friday morning, the airport declared a shutdown, which is expected to affect around 200,000 passengers in the immediate future, as well as flights in the coming days.
A Heathrow spokesperson said: “Heathrow is experiencing a significant power outage across the airport due to a large fire at a nearby electrical substation. Whilst fire crews are responding to the incident, we do not have clarity on when power may be reliably restored."
The spokesperson added, "We expect significant disruption over the coming days and passengers should not travel to the airport under any circumstances until the airport reopens."
One El Al flight expected to leave Israel for Heathrow at noon on Friday was canceled. El Al has requested passengers traveling to London to follow updates.