Heathrow Airport in London has been closed following a significant power outage caused by a massive fire at a nearby electrical substation. More than 1,000 flights have been affected, leading to widespread travel chaos, with airlines urging passengers not to travel to the airport. Eyewitness accounts and videos show towering flames at the substation, prompting emergency services to respond. As a result of the closure, airlines including Air India and Singapore Airlines have canceled numerous flights. The shutdown is expected to cause hundreds of millions of pounds in losses, affecting hundreds of thousands of travelers worldwide and causing numerous flight diversions.