London’s Heathrow Airport—one of the world’s largest travel hubs—said Friday it would resume flights after a fire at a nearby electrical substation caused a power outage, which halted operations and disrupted global travel.

Heathrow executives are defending their response to a fire that shut down Europe’s busiest air hub for almost a day.

Britain's Heathrow defended its decision to shut down operations at Europe's busiest airport last Friday as the blame game intensified over an 18-hour closure which cost airlines tens of millions of pounds and stranded thousands of passengers.

National Grid’s chief executive has insisted the electricity transmission network remained capable of feeding enough power to Heathrow throughout the airport’s closure last week, as airlines’ anger over the decision to shut down for nearly 24 hours grew.