The blaze forced Britain’s largest airport to cancel or divert more than 1,000 flights on Friday and removed a linchpin of global air travel. Counterterrorism police were investigating the cause of the fire.

London’s Heathrow Airport was completely shut down Friday because of a power outage due to a large fire nearby, causing massive disruption to one of the world’s busiest travel hubs. Follow for live updates.

London's main airport was shut down after a fire caused a power outage, with passengers advised to avoid Heathrow "until further notice."

London’s Heathrow Airport announced a complete shutdown all day Friday due to a “significant power outage” due to a large fire nearby, causing massive disruption to one of the world’s busiest travel hubs as flights were forced to turn back midair or divert to other locations.

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