The UK Secretary of State for Energy Security and Net Zero Ed Miliband announced Saturday that he is ordering an investigation into the substation fire.

Britain's aviation watchdog will consider Heathrow airport's resilience rules as part of a regular review, it said on Thursday, following a closure last week that disrupted global flight schedules and stranded thousands of passengers.

Heathrow did not immediately respond to a request for comment on its contingency planning. The closure is set to have days-long knock-on effects globally, leaving many passengers stranded as carriers reconfigure their networks to move planes and crews around.

LONDON — The British government on Saturday ordered an investigation into the country’s “energy resilience” after an electrical substation fire shut Heathrow Airport for almost a day and raised concerns about the U.K.’s ability to withstand disasters or attacks on critical infrastructure.

Sir Keir Starmer says he is 'deeply concerned' about the closure of Heathrow Airport as a result of a power cut caused by a fire on Friday.

Heathrow was shut in the early hours of Friday last week after the fire at the Hayes substation in west London hit electricity supplies.

A substation fire caused Heathrow Airport to go dark, forcing planes to be grounded even with backup generators.