Global air travel was thrown into chaos on Friday, March 21, 2025, after a massive fire at an electrical substation near Heathrow Airport triggered a full-day shutdown, stranding thousands of passengers and disrupting flight schedules across multiple continents.

The blaze, which erupted late Thursday night in west London, knocked out power to the airport and disabled its emergency back-up systems.

Heathrow, Europe’s busiest and the world’s fifth-busiest airport, was forced to cancel or divert over 1,300 scheduled flights, affecting nearly 300,000 passengers.

Airlines scrambled to redirect aircraft to alternate airports across the UK and mainland Europe, while several long-haul flights were forced to turn back mid-air.

Many passengers found themselves stranded in transit lounges, some without the necessary visas to leave the terminals.

Sarah Dalton, an aviation operations analyst, said the abrupt shutdown is a total logistical nightmare.

“The knock-on effect of so many aircraft being out of position will impact global flight schedules for days,” she added.

By the morning of March 21, 2025, the airport’s usually bustling terminals were eerily quiet, with only a few travelers walking away on foot, dragging their luggage.

Firefighters said they had brought the blaze under control, but power remained down at the airport, forcing authorities to extend the closure until midnight.

Heathrow officials advised passengers not to come to the airport and to contact their airlines for alternative arrangements.

“We apologize for the inconvenience,” the airport said in a statement, citing a “significant power outage.”

Energy Minister Ed Miliband said the cause of the fire was under investigation, though initial assessments indicated no foul play.

He confirmed that both primary and secondary power systems had failed, and engineers were working to activate a tertiary backup.

The sudden halt at one of the world’s most critical aviation hubs has led to a ripple effect across the global travel network. Industry experts warn that rescheduling affected flights, repositioning aircraft and crews, and accommodating displaced passengers could take days to resolve.

Travelers with connecting flights have been hit especially hard, with some stranded in international airports where they cannot legally leave the premises.