By Callum Keown

London's Heathrow Airport was closed Friday after a fire caused a power outage. While European airline stocks were hit, U.S. carriers were relatively unscathed in premarket trading.

British Airways, owned by parent company International Airlines Group $(IAG)$, was the worst affected with 265 flights canceled, or 37% of its schedule, according to flight-tracker FlightAware. In contrast, United Airlines had 21 cancellations, American Airlines 20, and Delta Air Lines 10 -- all less than 1% of the carriers' schedules. That is total global cancellations early Friday -- not just Heathrow flights.

Delta operates up to 15 daily flights to the U.S. from the U.K., according to its website, and that also includes those from London Gatwick and Edinburgh airports. United Airlines said seven of its flights had to be returned to their origin or other airports as a result of the incident.

The limited impact was reflected in the stock market. United, American and Delta were all less than 1% down ahead of the open Friday. IAG stock fell more than 1%, while AirFrance-KLM and Deutsche Lufthansa were both 1.4% lower.

"Due to a fire at an electrical substation supplying the airport, Heathrow is experiencing a significant power outage," the airport said in a post on X. "There will be no flights operating at Heathrow," it added.

Write to Callum Keown at callum.keown@dowjones.com

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March 21, 2025 07:41 ET (11:41 GMT)

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