This is a photo collection curated by AP photo editors.
One of the giant panda cub twins Leni or Lotti plays in the enclosure before venturing out on their first outdoor adventure, at the Zoo in Berlin, Germany, Thursday, March 20, 2025. (AP Photo/Ebrahim Noroozi)
One of the giant panda cub twins Leni or Lotti plays in the enclosure before venturing out on their first outdoor adventure, at the Zoo in Berlin, Germany, Thursday, March 20, 2025. (AP Photo/Ebrahim Noroozi)
Giant panda cub twins Leni and Lotti play in an outdoor area of the Panda Garden, during their first outdoor adventure, at the Zoo in Berlin, Germany, Thursday, March 20, 2025. (AP Photo/Ebrahim Noroozi)
One of the giant panda cub twins Leni or Lotti plays in the enclosure before venturing out on their first outdoor adventure, at the Zoo in Berlin, Germany, Thursday, March 20, 2025. (AP Photo/Ebrahim Noroozi)
One of the giant panda cub twins Leni or Lotti plays in an outdoor area of the Panda Garden, during their first outdoor adventure, at the Zoo in Berlin, Germany, Thursday, March 20, 2025. (AP Photo/Ebrahim Noroozi)
One of the giant panda cub twins Leni or Lotti plays in an outdoor area of the Panda Garden, during their first outdoor adventure, at the Zoo in Berlin, Germany, Thursday, March 20, 2025. (AP Photo/Ebrahim Noroozi)
An employee of the Berlin zoo hold one of the giant panda cub twins Leni or Lotti during their first outdoor adventure, at the Zoo in Berlin, Germany, Thursday, March 20, 2025. (AP Photo/Ebrahim Noroozi)
One of the giant panda cub twins Leni or Lotti plays in an outdoor area of the Panda Garden, during their first outdoor adventure, at the Zoo in Berlin, Germany, Thursday, March 20, 2025. (AP Photo/Ebrahim Noroozi)
An employee of the Berlin zoo holds one of the giant panda cub twins Leni or Lotti, during their first outdoor adventure, at the Zoo in Berlin, Germany, Thursday, March 20, 2025. (AP Photo/Ebrahim Noroozi)
Giant panda cub twins Leni and Lotti plays in an outdoor area of the Panda Garden, during their first outdoor adventure, at the Zoo in Berlin, Germany, Thursday, March 20, 2025. (AP Photo/Ebrahim Noroozi)
One of the giant panda cub twins Leni or Lotti plays in the enclosure before venturing out on their first outdoor adventure, at the Zoo in Berlin, Germany, Thursday, March 20, 2025. (AP Photo/Ebrahim Noroozi)
One of the giant panda cub twins Leni or Lotti plays in the enclosure before venturing out on their first outdoor adventure, at the Zoo in Berlin, Germany, Thursday, March 20, 2025. (AP Photo/Ebrahim Noroozi)
Click to Gallery
One of the giant panda cub twins Leni or Lotti plays in the enclosure before venturing out on their first outdoor adventure, at the Zoo in Berlin, Germany, Thursday, March 20, 2025. (AP Photo/Ebrahim Noroozi)
One of the giant panda cub twins Leni or Lotti plays in the enclosure before venturing out on their first outdoor adventure, at the Zoo in Berlin, Germany, Thursday, March 20, 2025. (AP Photo/Ebrahim Noroozi)
Giant panda cub twins Leni and Lotti play in an outdoor area of the Panda Garden, during their first outdoor adventure, at the Zoo in Berlin, Germany, Thursday, March 20, 2025. (AP Photo/Ebrahim Noroozi)
One of the giant panda cub twins Leni or Lotti plays in the enclosure before venturing out on their first outdoor adventure, at the Zoo in Berlin, Germany, Thursday, March 20, 2025. (AP Photo/Ebrahim Noroozi)
One of the giant panda cub twins Leni or Lotti plays in an outdoor area of the Panda Garden, during their first outdoor adventure, at the Zoo in Berlin, Germany, Thursday, March 20, 2025. (AP Photo/Ebrahim Noroozi)
One of the giant panda cub twins Leni or Lotti plays in an outdoor area of the Panda Garden, during their first outdoor adventure, at the Zoo in Berlin, Germany, Thursday, March 20, 2025. (AP Photo/Ebrahim Noroozi)
An employee of the Berlin zoo hold one of the giant panda cub twins Leni or Lotti during their first outdoor adventure, at the Zoo in Berlin, Germany, Thursday, March 20, 2025. (AP Photo/Ebrahim Noroozi)
One of the giant panda cub twins Leni or Lotti plays in an outdoor area of the Panda Garden, during their first outdoor adventure, at the Zoo in Berlin, Germany, Thursday, March 20, 2025. (AP Photo/Ebrahim Noroozi)
An employee of the Berlin zoo holds one of the giant panda cub twins Leni or Lotti, during their first outdoor adventure, at the Zoo in Berlin, Germany, Thursday, March 20, 2025. (AP Photo/Ebrahim Noroozi)
Giant panda cub twins Leni and Lotti plays in an outdoor area of the Panda Garden, during their first outdoor adventure, at the Zoo in Berlin, Germany, Thursday, March 20, 2025. (AP Photo/Ebrahim Noroozi)
One of the giant panda cub twins Leni or Lotti plays in the enclosure before venturing out on their first outdoor adventure, at the Zoo in Berlin, Germany, Thursday, March 20, 2025. (AP Photo/Ebrahim Noroozi)
One of the giant panda cub twins Leni or Lotti plays in the enclosure before venturing out on their first outdoor adventure, at the Zoo in Berlin, Germany, Thursday, March 20, 2025. (AP Photo/Ebrahim Noroozi)
LONDON (AP) — London Heathrow Airport said it was “fully operational” on Saturday, after an almost daylong closure sparked by an electrical substation fire. But thousands of passengers remained stuck, and airlines warned that severe disruption will last for days as they scramble to relocate planes and crews and get travelers to their destinations.
Friday's travel mayhem raised concerns about Britain's ability to withstand disasters or attacks on critical infrastructure. Inconvenienced passengers, angry airlines and concerned politicians all want answers about how one seemingly accidental fire could shut down Europe’s busiest air hub.
“This is a huge embarrassment for Heathrow airport. It’s a huge embarrassment for the country that a fire in one electricity substation can have such a devastating effect," said Toby Harris, a Labour Party politician who heads the National Preparedness Commission, a group that campaigns to improve resilience.
Heathrow said it had “hundreds of additional colleagues on hand in our terminals and we have added flights to today’s schedule to facilitate an extra 10,000 passengers." It advised passengers to check with their airline before going to the airport.
British Airways, Heathrow’s biggest airline, said it expected to operate about 85% of its 600 scheduled flights at the airport on Saturday. It said that "to recover an operation of our size after such a significant incident is extremely complex.”
While many passengers managed to resume stalled journeys, others remained in limbo.
Laura Fritschie from Kansas City was on vacation with her family in Ireland when she learned that her father had died. On Saturday she was stranded at Heathrow after her BA flight to Chicago was canceled at the last minute.
“I’m very frustrated," she said. “This was my first big vacation with my kids since my husband died, and ... now this. So I just want to go home.”
More than 1,300 flights were canceled and some 200,000 people stranded Friday after an overnight fire at a substation 2 miles (3.2 kilometers) away from the airport cut power to Heathrow, and to more than 60,000 properties.
Residents in west London described hearing a large explosion and then seeing a fireball and clouds of smoke when the blaze ripped through the substation. The fire was brought under control after seven hours, but the airport was shut for almost 18. A handful of flights took off and landed late Friday.
Police said they do not consider the fire suspicious, and the London Fire Brigade said its investigation would focus on the electrical distribution equipment at the substation.
Still, the huge impact of the fire left authorities facing questions about Britain’s creaking infrastructure. The government acknowledged that authorities had questions to answer and said a rigorous investigation was needed to make sure “this scale of disruption does not happen again.”
Harris, from the preparedness commission, said the airport shutdown points to a broader problem with Britain’s economy and infrastructure.
“The last 40, 50 years we’ve tried to make services more efficient,” he said. “We’ve stripped out redundancy, we’ve simplified processes. We’ve moved towards a sort of ‘just in time’ economy.
“There is an element where you have to make sure you’re available for ‘just in case.’ You have to plan for things going wrong.”
Heathrow chief executive Thomas Woldbye said he was “proud” of the way airport and airline staff had responded.
"Remember, the situation was not created at Heathrow Airport," he told the BBC. “The airport didn’t shut for days. We shut for hours."
He said Heathrow's backup power supply, designed for emergencies, worked as expected, but it wasn’t enough to run the whole airport, which uses as much energy as a small city.
“That’s how most airports operate," said Woldbye, who insisted “the same would happen in other airports" faced with a similar blaze.
Heathrow is one of the world’s busiest airports for international travel, and saw 83.9 million passengers last year.
Friday’s disruption was one of the most serious since the 2010 eruption of Iceland’s Eyjafjallajokull volcano, which shut Europe’s airspace for days.
Passengers on about 120 flights were in the air when Friday's closure was announced and found themselves landing in different cities, and even different countries.
Mark Doherty and his wife were halfway across the Atlantic when the inflight map showed their flight from New York’s John F. Kennedy Airport to Heathrow was turning around.
“I was like, you’re joking,” Doherty said before the pilot told passengers they were heading back to New York.
Doherty called the situation “typical England — got no back-up plan for something happens like this. There’s no contingency plan.”
Associated Press journalist Kwiyeon Ha at Heathrow Airport contributed to this report.
A British Airways plane approaches landing as Heathrow Airport slowly resumes flights after a fire cut power to Europe's busiest airport in London, Saturday, March 22, 2025.(AP Photo/Kirsty Wigglesworth)
Travellers wait outside the Terminal as Heathrow Airport slowly resumes flights after a fire cut power to Europe's busiest airport in London, Saturday, March 22, 2025.(AP Photo/Kirsty Wigglesworth)
Travellers check the information board in London, Saturday, March 22, 2025, as Heathrow Airport slowly resumes flights after a fire cut power to Europe's busiest airport.(AP Photo/Kirsty Wigglesworth)
The airport arrivals board at Terminal 5 as Britain's Heathrow Airport has closed for the full day Friday after an electrical substation fire knocked out its power, disrupting flights for hundreds of thousands of passengers at one of Europe's biggest travel hubs in London, Friday, March 21, 2025.(AP Photo/Kin Cheung)
A British Airways plane is parked at Terminal 5 as Britain's Heathrow Airport has closed for the full day Friday after an electrical substation fire knocked out its power, disrupting flights for hundreds of thousands of passengers at one of Europe's biggest travel hubs in London, Friday, March 21, 2025.(AP Photo/Kin Cheung)
Workers are seen as smoke rises from the North Hyde electrical substation, which caught fire last night, leading to the closure of the Heathrow Airport, in London, Friday March 21, 2025.(AP Photo/Kirsty Wigglesworth)
A handwritten sign at a Heathrow Airport tube station in London indicates the airport is closed on Friday March 21, 2025, following a fire at the North Hyde electrical substation the previous night.(AP Photo/Alberto Pezzali)
A plane is prepared whilst another airplane approaches landing at Heathrow Airport after a fire at an electrical substation shuttered Europe's busiest air travel hub in London, Friday, March 21, 2025.(AP Photo/Alberto Pezzali)
A traveller arrives at Terminal 5 as Heathrow Airport slowly resumes flights after a fire cut power to Europe's busiest airport in London, Saturday, March 22, 2025.(AP Photo/Kirsty Wigglesworth)
Travellers wait at Terminal 5 as Heathrow Airport slowly resumes flights after a fire cut power to Europe's busiest airport in London, Saturday, March 22, 2025.(AP Photo/Kirsty Wigglesworth)
Travellers arrive at Terminal 5 as Heathrow Airport slowly resumes flights after a fire cut power to Europe's busiest airport in London, Saturday, March 22, 2025.(AP Photo/Kirsty Wigglesworth)
Travellers arrive at Terminal 5 as Heathrow Airport slowly resumes flights after a fire cut power to Europe's busiest airport in London, Saturday, March 22, 2025.(AP Photo/Kirsty Wigglesworth)
Travellers arrives at Terminal 5 as Heathrow Airport slowly resumes flights after a fire cut power to Europe's busiest airport in London, Saturday, March 22, 2025.(AP Photo/Kirsty Wigglesworth)