The No. 4 busiest airport in the world is shut down, disrupting global travel and causing a major headache for business travelers.

Britain’s Heathrow Airport will remain closed all of Friday until 11:59 p.m. GMT after a major fire near the airport caused the area to lose power, per Reuters.

“Whilst fire crews are responding to the incident, we do not have clarity on when power may be reliably restored,” a spokesperson for the airport told Fox News. “To maintain the safety of our passengers and colleagues, we made the decision to close Heathrow until 23h59 on 21 March 2025.”

“We expect significant disruption over the coming days and passengers should not travel to the airport under any circumstances until the airport reopens,” the spokesperson added.

Around 5.7 million passengers traveled through Heathrow in February 2025, which was the busiest February on record, per Reuters. The airport had a record number (83.9 million) of passengers in 2024.

NBC reports that around 200,000 passengers and 1,300 flights are likely to be affected.

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… pic.twitter.com/7SWNJP8ojd

— Heathrow Airport (@HeathrowAirport) March 21, 2025

What caused the fire that shut down Heathrow Airport?

The BBC reports that the fire began at an electrical substation in Hayes, West London late Thursday evening and was under control by 6:28 GMT on Friday.

Some homes near the fire were also evacuated.

This is a breaking news story and will be updated.