UK's Heathrow airport ‘fully operational’ after Friday's fire

London's Heathrow airport is "fully operational," a spokesman said Saturday, a day after a fire at a power station forced the closure of Europe's biggest airport and caused chaos in global air travel.

Heathrow, one of the world's busiest airports, had to close for most of Friday due to a power outage caused by an overnight fire at the Hayes electricity transformer station in west London that supplies the area.

The closure of Heathrow, with scheduled flights to 80 countries around the world, caused a chain of disruptions to global air traffic as numerous flights had to be canceled or diverted.

The first planes began landing and taking off on Friday afternoon. They were mainly "repatriation flights" for "passengers who had been diverted to other European airports," officials explained.

"We can confirm that Heathrow is open and fully operational today," the spokesman said on Saturday morning.

"Airport teams are continuing to do all they can to assist passengers affected by yesterday's outage at an off-airport power substation," he added.

About 1,350 flights were affected by Friday's closure, according to the website Flightradar24.

On Saturday, delays and cancellations are expected before service returns to normal.

"We have hundreds of additional staff at our terminals and have added flights to today's schedule to facilitate an additional 10,000 passengers through the airport," the spokesman said. He also advised travelers to "check with their airline" for the latest flight information.

British Airways, the largest airline operating at Heathrow, expects "85%" of its scheduled flights to be able to fly on Saturday.

British Airways usually has about 600 flights departing and arriving at this airport on Saturdays.

Resuming operations "after such a significant incident is extremely complex," the airline explained. "It is likely that all customers traveling will experience delays," it warned.

More than 200,000 affected

On Friday, more than 100,000 British Airways customers were concerned by the airport closure. In total, at least 200,000 people were affected.

Some 230,000 passengers use Heathrow every day, totaling 83 million a year, making it one of the busiest airports in the world and the first in Europe.

The scale of the disruption raised questions about the vulnerability of one of the UK's most important transport infrastructures.

Firefighters said the cause of the fire, which broke out Thursday night, "did not appear suspicious" and that the investigation will focus "on electrical distribution equipment."

Earlier, London's Metropolitan Police announced that its anti-terrorism unit was leading the investigation into the fire given its repercussions, but that there was no indication of criminal intent at this stage.

Under the heading "chaos," several British newspapers were asking on their front pages Saturday how such an incident could have occurred.

The airport's director, Thomas Woldbye, apologized for "the inconvenience" caused to travelers, and assured that an incident "on such a scale" was "unprecedented."

The airport has several sources of electricity and emergency generators. However, these systems are not designed to guarantee the full operation of the infrastructure, according to its operator.